samples/third_party/dromaeo/tests/dom-traverse-dom.html - Issue 10910013: Remove instances of dart:dom_deprecated from outside of lib/html and lib/dom. Part 1 of many.

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Issue 10910013: Remove instances of dart:dom_deprecated from outside of lib/html and lib/dom. Part 1 of many. (Closed) Base URL: http://dart.googlecode.com/svn/branches/bleeding_edge/dart/

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1 <html>

2 <head>

3 <script type="application/dart" src="dom-traverse-dom.dart"></script>

4 <script src="http://dart.googlecode.com/svn/branches/bleeding_edge/dart/client/d art.js"></script>

5 </head>

6 <body>

7 <div class="head">

8 <p><a href="http://www.w3.org/"><img height=48 alt=W3C src="http://www.w3.org /Icons/w3c_home" width=72></a>

9

10 <h1 id="title">Selectors</h1>

11

12 <h2>W3C Working Draft 15 December 2005</h2>

13

14 <dl>

15

16 <dt>This version:

17

18 <dd><a href="http://www.w3.org/TR/2005/WD-css3-selectors-20051215">

19 http://www.w3.org/TR/2005/WD-css3-selectors-20051215</a>

20

21 <dt>Latest version:

22

23 <dd><a href="http://www.w3.org/TR/css3-selectors">

24 http://www.w3.org/TR/css3-selectors</a>

25

26 <dt>Previous version:

27

28 <dd><a href="http://www.w3.org/TR/2001/CR-css3-selectors-20011113">

29 http://www.w3.org/TR/2001/CR-css3-selectors-20011113</a>

30

31 <dt><a name=editors-list></a>Editors:

32

33 <dd class="vcard"><span class="fn">Daniel Glazman</span> (Invited Expert)</d d>

34

35 <dd class="vcard"><a lang="tr" class="url fn" href="http://www.tantek.com/"> Tantek Çelik</a> (Invited Expert)

36

37 <dd class="vcard"><a href="mailto:ian@hixie.ch" class="url fn">Ian Hickson</ a> (<span

38 class="company"><a href="http://www.google.com/">Google</a></span>)

39

40 <dd class="vcard"><span class="fn">Peter Linss</span> (former editor, <span class="company"><a

41 href="http://www.netscape.com/">Netscape/AOL</a></span>)

42

43 <dd class="vcard"><span class="fn">John Williams</span> (former editor, <spa n class="company"><a

44 href="http://www.quark.com/">Quark, Inc.</a></span>)

45

46 </dl>

47

48 <p class="copyright"><a

49 href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">

50 Copyright</a> © 2005 <a href="http://www.w3.org/"><abbr

51 title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup>

52 (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts

53 Institute of Technology">MIT</abbr></a>, <a

54 href="http://www.ercim.org/"><acronym title="European Research

55 Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a

56 href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C

57 <a

58 href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liabili ty</a>,

59 <a

60 href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark </a>,

61 <a

62 href="http://www.w3.org/Consortium/Legal/copyright-documents">document

63 use</a> rules apply.

64

65 <hr title="Separator for header">

66

67 </div>

68

69 <h2><a name=abstract></a>Abstract</h2>

70

71 <p><em>Selectors</em> are patterns that match against elements in a

72 tree. Selectors have been optimized for use with HTML and XML, and

73 are designed to be usable in performance-critical code.</p>

74

75 <p><acronym title="Cascading Style Sheets">CSS</acronym> (Cascading

76 Style Sheets) is a language for describing the rendering of <acronym

77 title="Hypertext Markup Language">HTML</acronym> and <acronym

78 title="Extensible Markup Language">XML</acronym> documents on

79 screen, on paper, in speech, etc. CSS uses Selectors for binding

80 style properties to elements in the document. This document

81 describes extensions to the selectors defined in CSS level 2. These

82 extended selectors will be used by CSS level 3.

83

84 <p>Selectors define the following function:</p>

85

86 <pre>expression ∗ element → boolean</pre>

87

88 <p>That is, given an element and a selector, this specification

89 defines whether that element matches the selector.</p>

90

91 <p>These expressions can also be used, for instance, to select a set

92 of elements, or a single element from a set of elements, by

93 evaluating the expression across all the elements in a

94 subtree. <acronym title="Simple Tree Transformation

95 Sheets">STTS</acronym> (Simple Tree Transformation Sheets), a

96 language for transforming XML trees, uses this mechanism. <a href="#refsSTTS"> [STTS]</a></p>

97

98 <h2><a name=status></a>Status of this document</h2>

99

100 <p><em>This section describes the status of this document at the

101 time of its publication. Other documents may supersede this

102 document. A list of current W3C publications and the latest revision

103 of this technical report can be found in the <a

104 href="http://www.w3.org/TR/">W3C technical reports index at

105 http://www.w3.org/TR/.</a></em></p>

106

107 <p>This document describes the selectors that already exist in <a

108 href="#refsCSS1"><abbr title="CSS level 1">CSS1</abbr></a> and <a

109 href="#refsCSS21"><abbr title="CSS level 2">CSS2</abbr></a>, and

110 also proposes new selectors for <abbr title="CSS level

111 3">CSS3</abbr> and other languages that may need them.</p>

112

113 <p>The CSS Working Group doesn't expect that all implementations of

114 CSS3 will have to implement all selectors. Instead, there will

115 probably be a small number of variants of CSS3, called profiles. For

116 example, it may be that only a profile for interactive user agents

117 will include all of the selectors.</p>

118

119 <p>This specification is a last call working draft for the the <a

120 href="http://www.w3.org/Style/CSS/members">CSS Working Group</a>

121 (<a href="/Style/">Style Activity</a>). This

122 document is a revision of the <a

123 href="http://www.w3.org/TR/2001/CR-css3-selectors-20011113/">Candidate

124 Recommendation dated 2001 November 13</a>, and has incorporated

125 implementation feedback received in the past few years. It is

126 expected that this last call will proceed straight to Proposed

127 Recommendation stage since it is believed that interoperability will

128 be demonstrable.</p>

129

130 <p>All persons are encouraged to review and implement this

131 specification and return comments to the (<a

132 href="http://lists.w3.org/Archives/Public/www-style/">archived</a>)

133 public mailing list <a

134 href="http://www.w3.org/Mail/Lists.html#www-style">www-style</a>

135 (see <a href="http://www.w3.org/Mail/Request">instructions</a>). W3C

136 Members can also send comments directly to the CSS Working

137 Group.

138 The deadline for comments is 14 January 2006.</p>

139

140 <p>This is still a draft document and may be updated, replaced, or

141 obsoleted by other documents at any time. It is inappropriate to

142 cite a W3C Working Draft as other than "work in progress".

143

144 <p>This document may be available in <a

145 href="http://www.w3.org/Style/css3-selectors-updates/translations">translation </a>.

146 The English version of this specification is the only normative

147 version.

148

149 <div class="subtoc">

150

151 <h2 id="test10"><a name=contents>Table of contents</a></h2>

152

153 <ul class="toc">

154 <li class="tocline2"><a href="#context">1. Introduction</a>

155 <ul>

156 <li><a href="#dependencies">1.1. Dependencies</a> </li>

157 <li><a href="#terminology">1.2. Terminology</a> </li>

158 <li><a href="#changesFromCSS2">1.3. Changes from CSS2</a> </li>

159 </ul>

160 <li class="tocline2"><a href="#selectors">2. Selectors</a>

161 <li class="tocline2"><a href="#casesens">3. Case sensitivity</a>

162 <li class="tocline2"><a href="#selector-syntax">4. Selector syntax</a>

163 <li class="tocline2"><a href="#grouping">5. Groups of selectors</a>

164 <li class="tocline2"><a href="#simple-selectors">6. Simple selectors</a>

165 <ul class="toc">

166 <li class="tocline3"><a href="#type-selectors">6.1. Type selectors</a>

167 <ul class="toc">

168 <li class="tocline4"><a href="#typenmsp">6.1.1. Type selectors and names paces</a></li>

169 </ul>

170 <li class="tocline3"><a href="#universal-selector">6.2. Universal selector </a>

171 <ul>

172 <li><a href="#univnmsp">6.2.1. Universal selector and namespaces</a></li >

173 </ul>

174 <li class="tocline3"><a href="#attribute-selectors">6.3. Attribute selecto rs</a>

175 <ul class="toc">

176 <li class="tocline4"><a href="#attribute-representation">6.3.1. Represen tation of attributes and attributes values</a>

177 <li><a href="#attribute-substrings">6.3.2. Substring matching attribute selectors</a>

178 <li class="tocline4"><a href="#attrnmsp">6.3.3. Attribute selectors and namespaces</a>

179 <li class="tocline4"><a href="#def-values">6.3.4. Default attribute valu es in DTDs</a></li>

180 </ul>

181 <li class="tocline3"><a href="#class-html">6.4. Class selectors</a>

182 <li class="tocline3"><a href="#id-selectors">6.5. ID selectors</a>

183 <li class="tocline3"><a href="#pseudo-classes">6.6. Pseudo-classes</a>

184 <ul class="toc">

185 <li class="tocline4"><a href="#dynamic-pseudos">6.6.1. Dynamic pseudo-cl asses</a>

186 <li class="tocline4"><a href="#target-pseudo">6.6.2. The :target pseudo- class</a>

187 <li class="tocline4"><a href="#lang-pseudo">6.6.3. The :lang() pseudo-cl ass</a>

188 <li class="tocline4"><a href="#UIstates">6.6.4. UI element states pseudo -classes</a>

189 <li class="tocline4"><a href="#structural-pseudos">6.6.5. Structural pse udo-classes</a>

190 <ul>

191 <li><a href="#root-pseudo">:root pseudo-class</a>

192 <li><a href="#nth-child-pseudo">:nth-child() pseudo-class</a>

193 <li><a href="#nth-last-child-pseudo">:nth-last-child()</a>

194 <li><a href="#nth-of-type-pseudo">:nth-of-type() pseudo-class</a>

195 <li><a href="#nth-last-of-type-pseudo">:nth-last-of-type()</a>

196 <li><a href="#first-child-pseudo">:first-child pseudo-class</a>

197 <li><a href="#last-child-pseudo">:last-child pseudo-class</a>

198 <li><a href="#first-of-type-pseudo">:first-of-type pseudo-class</a>

199 <li><a href="#last-of-type-pseudo">:last-of-type pseudo-class</a>

200 <li><a href="#only-child-pseudo">:only-child pseudo-class</a>

201 <li><a href="#only-of-type-pseudo">:only-of-type pseudo-class</a>

202 <li><a href="#empty-pseudo">:empty pseudo-class</a></li>

203 </ul>

204 <li class="tocline4"><a href="#negation">6.6.7. The negation pseudo-clas s</a></li>

205 </ul>

206 </li>

207 </ul>

208 <li><a href="#pseudo-elements">7. Pseudo-elements</a>

209 <ul>

210 <li><a href="#first-line">7.1. The ::first-line pseudo-element</a>

211 <li><a href="#first-letter">7.2. The ::first-letter pseudo-element</a>

212 <li><a href="#UIfragments">7.3. The ::selection pseudo-element</a>

213 <li><a href="#gen-content">7.4. The ::before and ::after pseudo-elements</ a></li>

214 </ul>

215 <li class="tocline2"><a href="#combinators">8. Combinators</a>

216 <ul class="toc">

217 <li class="tocline3"><a href="#descendant-combinators">8.1. Descendant com binators</a>

218 <li class="tocline3"><a href="#child-combinators">8.2. Child combinators</ a>

219 <li class="tocline3"><a href="#sibling-combinators">8.3. Sibling combinato rs</a>

220 <ul class="toc">

221 <li class="tocline4"><a href="#adjacent-sibling-combinators">8.3.1. Adja cent sibling combinator</a>

222 <li class="tocline4"><a href="#general-sibling-combinators">8.3.2. Gener al sibling combinator</a></li>

223 </ul>

224 </li>

225 </ul>

226 <li class="tocline2"><a href="#specificity">9. Calculating a selector's spec ificity</a>

227 <li class="tocline2"><a href="#w3cselgrammar">10. The grammar of Selectors</ a>

228 <ul class="toc">

229 <li class="tocline3"><a href="#grammar">10.1. Grammar</a>

230 <li class="tocline3"><a href="#lex">10.2. Lexical scanner</a></li>

231 </ul>

232 <li class="tocline2"><a href="#downlevel">11. Namespaces and down-level clie nts</a>

233 <li class="tocline2"><a href="#profiling">12. Profiles</a>

234 <li><a href="#Conformance">13. Conformance and requirements</a>

235 <li><a href="#Tests">14. Tests</a>

236 <li><a href="#ACKS">15. Acknowledgements</a>

237 <li class="tocline2"><a href="#references">16. References</a>

238 </ul>

239

240 </div>

241

242 <h2><a name=context>1. Introduction</a></h2>

243

244 <h3><a name=dependencies></a>1.1. Dependencies</h3>

245

246 <p>Some features of this specification are specific to CSS, or have

247 particular limitations or rules specific to CSS. In this

248 specification, these have been described in terms of CSS2.1. <a

249 href="#refsCSS21">[CSS21]</a></p>

250

251 <h3><a name=terminology></a>1.2. Terminology</h3>

252

253 <p>All of the text of this specification is normative except

254 examples, notes, and sections explicitly marked as

255 non-normative.</p>

256

257 <h3><a name=changesFromCSS2></a>1.3. Changes from CSS2</h3>

258

259 <p><em>This section is non-normative.</em></p>

260

261 <p>The main differences between the selectors in CSS2 and those in

262 Selectors are:

263

264 <ul>

265

266 <li>the list of basic definitions (selector, group of selectors,

267 simple selector, etc.) has been changed; in particular, what was

268 referred to in CSS2 as a simple selector is now called a sequence

269 of simple selectors, and the term "simple selector" is now used for

270 the components of this sequence</li>

271

272 <li>an optional namespace component is now allowed in type element

273 selectors, the universal selector and attribute selectors</li>

274

275 <li>a <a href="#general-sibling-combinators">new combinator</a> has been intr oduced</li>

276

277 <li>new simple selectors including substring matching attribute

278 selectors, and new pseudo-classes</li>

279

280 <li>new pseudo-elements, and introduction of the "::" convention

281 for pseudo-elements</li>

282

283 <li>the grammar has been rewritten</li>

284

285 <li>profiles to be added to specifications integrating Selectors

286 and defining the set of selectors which is actually supported by

287 each specification</li>

288

289 <li>Selectors are now a CSS3 Module and an independent

290 specification; other specifications can now refer to this document

291 independently of CSS</li>

292

293 <li>the specification now has its own test suite</li>

294

295 </ul>

296

297 <h2><a name=selectors></a>2. Selectors</h2>

298

299 <p><em>This section is non-normative, as it merely summarizes the

300 following sections.</em></p>

301

302 <p>A Selector represents a structure. This structure can be used as a

303 condition (e.g. in a CSS rule) that determines which elements a

304 selector matches in the document tree, or as a flat description of the

305 HTML or XML fragment corresponding to that structure.</p>

306

307 <p>Selectors may range from simple element names to rich contextual

308 representations.</p>

309

310 <p>The following table summarizes the Selector syntax:</p>

311

312 <table class="selectorsReview">

313 <thead>

314 <tr>

315 <th class="pattern">Pattern</th>

316 <th class="meaning">Meaning</th>

317 <th class="described">Described in section</th>

318 <th class="origin">First defined in CSS level</th></tr>

319 <tbody>

320 <tr>

321 <td class="pattern">*</td>

322 <td class="meaning">any element</td>

323 <td class="described"><a

324 href="#universal-selector">Universal

325 selector</a></td>

326 <td class="origin">2</td></tr>

327 <tr>

328 <td class="pattern">E</td>

329 <td class="meaning">an element of type E</td>

330 <td class="described"><a

331 href="#type-selectors">Type selector</a></td>

332 <td class="origin">1</td></tr>

333 <tr>

334 <td class="pattern">E[foo]</td>

335 <td class="meaning">an E element with a "foo" attribute</td>

336 <td class="described"><a

337 href="#attribute-selectors">Attribute

338 selectors</a></td>

339 <td class="origin">2</td></tr>

340 <tr>

341 <td class="pattern">E[foo="bar"]</td>

342 <td class="meaning">an E element whose "foo" attribute value is exactly

343 equal to "bar"</td>

344 <td class="described"><a

345 href="#attribute-selectors">Attribute

346 selectors</a></td>

347 <td class="origin">2</td></tr>

348 <tr>

349 <td class="pattern">E[foo~="bar"]</td>

350 <td class="meaning">an E element whose "foo" attribute value is a list of

351 space-separated values, one of which is exactly equal to "bar"</td>

352 <td class="described"><a

353 href="#attribute-selectors">Attribute

354 selectors</a></td>

355 <td class="origin">2</td></tr>

356 <tr>

357 <td class="pattern">E[foo^="bar"]</td>

358 <td class="meaning">an E element whose "foo" attribute value begins exactly

359 with the string "bar"</td>

360 <td class="described"><a

361 href="#attribute-selectors">Attribute

362 selectors</a></td>

363 <td class="origin">3</td></tr>

364 <tr>

365 <td class="pattern">E[foo$="bar"]</td>

366 <td class="meaning">an E element whose "foo" attribute value ends exactly

367 with the string "bar"</td>

368 <td class="described"><a

369 href="#attribute-selectors">Attribute

370 selectors</a></td>

371 <td class="origin">3</td></tr>

372 <tr>

373 <td class="pattern">E[foo*="bar"]</td>

374 <td class="meaning">an E element whose "foo" attribute value contains the

375 substring "bar"</td>

376 <td class="described"><a

377 href="#attribute-selectors">Attribute

378 selectors</a></td>

379 <td class="origin">3</td></tr>

380 <tr>

381 <td class="pattern">E[hreflang\|="en"]</td>

382 <td class="meaning">an E element whose "hreflang" attribute has a hyphen-sep arated

383 list of values beginning (from the left) with "en"</td>

384 <td class="described"><a

385 href="#attribute-selectors">Attribute

386 selectors</a></td>

387 <td class="origin">2</td></tr>

388 <tr>

389 <td class="pattern">E:root</td>

390 <td class="meaning">an E element, root of the document</td>

391 <td class="described"><a

392 href="#structural-pseudos">Structural

393 pseudo-classes</a></td>

394 <td class="origin">3</td></tr>

395 <tr>

396 <td class="pattern">E:nth-child(n)</td>

397 <td class="meaning">an E element, the n-th child of its parent</td>

398 <td class="described"><a

399 href="#structural-pseudos">Structural

400 pseudo-classes</a></td>

401 <td class="origin">3</td></tr>

402 <tr>

403 <td class="pattern">E:nth-last-child(n)</td>

404 <td class="meaning">an E element, the n-th child of its parent, counting

405 from the last one</td>

406 <td class="described"><a

407 href="#structural-pseudos">Structural

408 pseudo-classes</a></td>

409 <td class="origin">3</td></tr>

410 <tr>

411 <td class="pattern">E:nth-of-type(n)</td>

412 <td class="meaning">an E element, the n-th sibling of its type</td>

413 <td class="described"><a

414 href="#structural-pseudos">Structural

415 pseudo-classes</a></td>

416 <td class="origin">3</td></tr>

417 <tr>

418 <td class="pattern">E:nth-last-of-type(n)</td>

419 <td class="meaning">an E element, the n-th sibling of its type, counting

420 from the last one</td>

421 <td class="described"><a

422 href="#structural-pseudos">Structural

423 pseudo-classes</a></td>

424 <td class="origin">3</td></tr>

425 <tr>

426 <td class="pattern">E:first-child</td>

427 <td class="meaning">an E element, first child of its parent</td>

428 <td class="described"><a

429 href="#structural-pseudos">Structural

430 pseudo-classes</a></td>

431 <td class="origin">2</td></tr>

432 <tr>

433 <td class="pattern">E:last-child</td>

434 <td class="meaning">an E element, last child of its parent</td>

435 <td class="described"><a

436 href="#structural-pseudos">Structural

437 pseudo-classes</a></td>

438 <td class="origin">3</td></tr>

439 <tr>

440 <td class="pattern">E:first-of-type</td>

441 <td class="meaning">an E element, first sibling of its type</td>

442 <td class="described"><a

443 href="#structural-pseudos">Structural

444 pseudo-classes</a></td>

445 <td class="origin">3</td></tr>

446 <tr>

447 <td class="pattern">E:last-of-type</td>

448 <td class="meaning">an E element, last sibling of its type</td>

449 <td class="described"><a

450 href="#structural-pseudos">Structural

451 pseudo-classes</a></td>

452 <td class="origin">3</td></tr>

453 <tr>

454 <td class="pattern">E:only-child</td>

455 <td class="meaning">an E element, only child of its parent</td>

456 <td class="described"><a

457 href="#structural-pseudos">Structural

458 pseudo-classes</a></td>

459 <td class="origin">3</td></tr>

460 <tr>

461 <td class="pattern">E:only-of-type</td>

462 <td class="meaning">an E element, only sibling of its type</td>

463 <td class="described"><a

464 href="#structural-pseudos">Structural

465 pseudo-classes</a></td>

466 <td class="origin">3</td></tr>

467 <tr>

468 <td class="pattern">E:empty</td>

469 <td class="meaning">an E element that has no children (including text

470 nodes)</td>

471 <td class="described"><a

472 href="#structural-pseudos">Structural

473 pseudo-classes</a></td>

474 <td class="origin">3</td></tr>

475 <tr>

476 <td class="pattern">E:link<br>E:visited</td>

477 <td class="meaning">an E element being the source anchor of a hyperlink of

478 which the target is not yet visited (:link) or already visited

479 (:visited)</td>

480 <td class="described"><a

481 href="#link">The link

482 pseudo-classes</a></td>

483 <td class="origin">1</td></tr>

484 <tr>

485 <td class="pattern">E:active<br>E:hover<br>E:focus</td>

486 <td class="meaning">an E element during certain user actions</td>

487 <td class="described"><a

488 href="#useraction-pseudos">The user

489 action pseudo-classes</a></td>

490 <td class="origin">1 and 2</td></tr>

491 <tr>

492 <td class="pattern">E:target</td>

493 <td class="meaning">an E element being the target of the referring URI</td>

494 <td class="described"><a

495 href="#target-pseudo">The target

496 pseudo-class</a></td>

497 <td class="origin">3</td></tr>

498 <tr>

499 <td class="pattern">E:lang(fr)</td>

500 <td class="meaning">an element of type E in language "fr" (the document

501 language specifies how language is determined)</td>

502 <td class="described"><a

503 href="#lang-pseudo">The :lang()

504 pseudo-class</a></td>

505 <td class="origin">2</td></tr>

506 <tr>

507 <td class="pattern">E:enabled<br>E:disabled</td>

508 <td class="meaning">a user interface element E which is enabled or

509 disabled</td>

510 <td class="described"><a

511 href="#UIstates">The UI element states

512 pseudo-classes</a></td>

513 <td class="origin">3</td></tr>

514 <tr>

515 <td class="pattern">E:checked<!--<br>E:indeterminate--></td>

516 <td class="meaning">a user interface element E which is checked<!-- or in an

517 indeterminate state--> (for instance a radio-button or checkbox)</td>

518 <td class="described"><a

519 href="#UIstates">The UI element states

520 pseudo-classes</a></td>

521 <td class="origin">3</td></tr>

522 <tr>

523 <td class="pattern">E::first-line</td>

524 <td class="meaning">the first formatted line of an E element</td>

525 <td class="described"><a

526 href="#first-line">The ::first-line

527 pseudo-element</a></td>

528 <td class="origin">1</td></tr>

529 <tr>

530 <td class="pattern">E::first-letter</td>

531 <td class="meaning">the first formatted letter of an E element</td>

532 <td class="described"><a

533 href="#first-letter">The ::first-letter

534 pseudo-element</a></td>

535 <td class="origin">1</td></tr>

536 <tr>

537 <td class="pattern">E::selection</td>

538 <td class="meaning">the portion of an E element that is currently

539 selected/highlighted by the user</td>

540 <td class="described"><a

541 href="#UIfragments">The UI element

542 fragments pseudo-elements</a></td>

543 <td class="origin">3</td></tr>

544 <tr>

545 <td class="pattern">E::before</td>

546 <td class="meaning">generated content before an E element</td>

547 <td class="described"><a

548 href="#gen-content">The ::before

549 pseudo-element</a></td>

550 <td class="origin">2</td></tr>

551 <tr>

552 <td class="pattern">E::after</td>

553 <td class="meaning">generated content after an E element</td>

554 <td class="described"><a

555 href="#gen-content">The ::after

556 pseudo-element</a></td>

557 <td class="origin">2</td></tr>

558 <tr>

559 <td class="pattern">E.warning</td>

560 <td class="meaning">an E element whose class is

561 "warning" (the document language specifies how class is determined).</td>

562 <td class="described"><a

563 href="#class-html">Class

564 selectors</a></td>

565 <td class="origin">1</td></tr>

566 <tr>

567 <td class="pattern">E#myid</td>

568 <td class="meaning">an E element with ID equal to "myid".</td>

569 <td class="described"><a

570 href="#id-selectors">ID

571 selectors</a></td>

572 <td class="origin">1</td></tr>

573 <tr>

574 <td class="pattern">E:not(s)</td>

575 <td class="meaning">an E element that does not match simple selector s</td>

576 <td class="described"><a

577 href="#negation">Negation

578 pseudo-class</a></td>

579 <td class="origin">3</td></tr>

580 <tr>

581 <td class="pattern">E F</td>

582 <td class="meaning">an F element descendant of an E element</td>

583 <td class="described"><a

584 href="#descendant-combinators">Descendant

585 combinator</a></td>

586 <td class="origin">1</td></tr>

587 <tr>

588 <td class="pattern">E > F</td>

589 <td class="meaning">an F element child of an E element</td>

590 <td class="described"><a

591 href="#child-combinators">Child

592 combinator</a></td>

593 <td class="origin">2</td></tr>

594 <tr>

595 <td class="pattern">E + F</td>

596 <td class="meaning">an F element immediately preceded by an E element</td>

597 <td class="described"><a

598 href="#adjacent-sibling-combinators">Adjacent sibling combinator</a></td>

599 <td class="origin">2</td></tr>

600 <tr>

601 <td class="pattern">E ~ F</td>

602 <td class="meaning">an F element preceded by an E element</td>

603 <td class="described"><a

604 href="#general-sibling-combinators">General sibling combinator</a></td>

605 <td class="origin">3</td></tr></tbody></table>

606

607 <p>The meaning of each selector is derived from the table above by

608 prepending "matches" to the contents of each cell in the "Meaning"

609 column.</p>

610

611 <h2><a name=casesens>3. Case sensitivity</a></h2>

612

613 <p>The case sensitivity of document language element names, attribute

614 names, and attribute values in selectors depends on the document

615 language. For example, in HTML, element names are case-insensitive,

616 but in XML, they are case-sensitive.</p>

617

618 <h2><a name=selector-syntax>4. Selector syntax</a></h2>

619

620 <p>A <dfn><a name=selector>selector</a></dfn> is a chain of one

621 or more <a href="#sequence">sequences of simple selectors</a>

622 separated by <a href="#combinators">combinators</a>.</p>

623

624 <p>A <dfn><a name=sequence>sequence of simple selectors</a></dfn>

625 is a chain of <a href="#simple-selectors-dfn">simple selectors</a>

626 that are not separated by a <a href="#combinators">combinator</a>. It

627 always begins with a <a href="#type-selectors">type selector</a> or a

628 <a href="#universal-selector">universal selector</a>. No other type

629 selector or universal selector is allowed in the sequence.</p>

630

631 <p>A <dfn><a name=simple-selectors-dfn></a><a

632 href="#simple-selectors">simple selector</a></dfn> is either a <a

633 href="#type-selectors">type selector</a>, <a

634 href="#universal-selector">universal selector</a>, <a

635 href="#attribute-selectors">attribute selector</a>, <a

636 href="#class-html">class selector</a>, <a

637 href="#id-selectors">ID selector</a>, <a

638 href="#content-selectors">content selector</a>, or <a

639 href="#pseudo-classes">pseudo-class</a>. One <a

640 href="#pseudo-elements">pseudo-element</a> may be appended to the last

641 sequence of simple selectors.</p>

642

643 <p><dfn>Combinators</dfn> are: white space, "greater-than

644 sign" (U+003E, <code>></code>), "plus sign" (U+002B,

645 <code>+</code>) and "tilde" (U+007E, <code>~</code>). White

646 space may appear between a combinator and the simple selectors around

647 it. <a name=whitespace></a>Only the characters "space" (U+0020), "tab"

648 (U+0009), "line feed" (U+000A), "carriage return" (U+000D), and "form

649 feed" (U+000C) can occur in white space. Other space-like characters,

650 such as "em-space" (U+2003) and "ideographic space" (U+3000), are

651 never part of white space.</p>

652

653 <p>The elements of a document tree that are represented by a selector

654 are the <dfn><a name=subject></a>subjects of the selector</dfn>. A

655 selector consisting of a single sequence of simple selectors

656 represents any element satisfying its requirements. Prepending another

657 sequence of simple selectors and a combinator to a sequence imposes

658 additional matching constraints, so the subjects of a selector are

659 always a subset of the elements represented by the last sequence of

660 simple selectors.</p>

661

662 <p>An empty selector, containing no sequence of simple selectors and

663 no pseudo-element, is an <a href="#Conformance">invalid

664 selector</a>.</p>

665

666 <h2><a name=grouping>5. Groups of selectors</a></h2>

667

668 <p>When several selectors share the same declarations, they may be

669 grouped into a comma-separated list. (A comma is U+002C.)</p>

670

671 <div class="example">

672 <p>CSS examples:</p>

673 <p>In this example, we condense three rules with identical

674 declarations into one. Thus,</p>

675 <pre>h1 { font-family: sans-serif }

676 h2 { font-family: sans-serif }

677 h3 { font-family: sans-serif }</pre>

678 <p>is equivalent to:</p>

679 <pre>h1, h2, h3 { font-family: sans-serif }</pre>

680 </div>

681

682 <p><strong>Warning</strong>: the equivalence is true in this example

683 because all the selectors are valid selectors. If just one of these

684 selectors were invalid, the entire group of selectors would be

685 invalid. This would invalidate the rule for all three heading

686 elements, whereas in the former case only one of the three individual

687 heading rules would be invalidated.</p>

688

689

690 <h2><a name=simple-selectors>6. Simple selectors</a></h2>

691

692 <h3><a name=type-selectors>6.1. Type selector</a></h3>

693

694 <p>A <dfn>type selector</dfn> is the name of a document language

695 element type. A type selector represents an instance of the element

696 type in the document tree.</p>

697

698 <div class="example">

699 <p>Example:</p>

700 <p>The following selector represents an <code>h1</code> element in the document tree:</p>

701 <pre>h1</pre>

702 </div>

703

704

705 <h4><a name=typenmsp>6.1.1. Type selectors and namespaces</a></h4>

706

707 <p>Type selectors allow an optional namespace (<a

708 href="#refsXMLNAMES">[XMLNAMES]</a>) component. A namespace prefix

709 that has been previously declared may be prepended to the element name

710 separated by the namespace separator "vertical bar"

711 (U+007C, <code>\|</code>).</p>

712

713 <p>The namespace component may be left empty to indicate that the

714 selector is only to represent elements with no declared namespace.</p>

715

716 <p>An asterisk may be used for the namespace prefix, indicating that

717 the selector represents elements in any namespace (including elements

718 with no namespace).</p>

719

720 <p>Element type selectors that have no namespace component (no

721 namespace separator), represent elements without regard to the

722 element's namespace (equivalent to "<code>*\|</code>") unless a default

723 namespace has been declared. If a default namespace has been declared,

724 the selector will represent only elements in the default

725 namespace.</p>

726

727 <p>A type selector containing a namespace prefix that has not been

728 previously declared is an <a href="#Conformance">invalid</a> selector.

729 The mechanism for declaring a namespace prefix is left up to the

730 language implementing Selectors. In CSS, such a mechanism is defined

731 in the General Syntax module.</p>

732

733 <p>In a namespace-aware client, element type selectors will only match

734 against the <a

735 href="http://www.w3.org/TR/REC-xml-names/#NT-LocalPart">local part</a>

736 of the element's <a

737 href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">qualified

738 name</a>. See <a href="#downlevel">below</a> for notes about matching

739 behaviors in down-level clients.</p>

740

741 <p>In summary:</p>

742

743 <dl>

744 <dt><code>ns\|E</code></dt>

745 <dd>elements with name E in namespace ns</dd>

746 <dt><code>*\|E</code></dt>

747 <dd>elements with name E in any namespace, including those without any

748 declared namespace</dd>

749 <dt><code>\|E</code></dt>

750 <dd>elements with name E without any declared namespace</dd>

751 <dt><code>E</code></dt>

752 <dd>if no default namespace has been specified, this is equivalent to *\|E.

753 Otherwise it is equivalent to ns\|E where ns is the default namespace.</dd>

754 </dl>

755

756 <div class="example">

757 <p>CSS examples:</p>

758

759 <pre>@namespace foo url(http://www.example.com);

760 foo\|h1 { color: blue }

761 foo\|* { color: yellow }

762 \|h1 { color: red }

763 *\|h1 { color: green }

764 h1 { color: green }</pre>

765

766 <p>The first rule will match only <code>h1</code> elements in the

767 "http://www.example.com" namespace.</p>

768

769 <p>The second rule will match all elements in the

770 "http://www.example.com" namespace.</p>

771

772 <p>The third rule will match only <code>h1</code> elements without

773 any declared namespace.</p>

774

775 <p>The fourth rule will match <code>h1</code> elements in any

776 namespace (including those without any declared namespace).</p>

777

778 <p>The last rule is equivalent to the fourth rule because no default

779 namespace has been defined.</p>

780

781 </div>

782

783 <h3><a name=universal-selector>6.2. Universal selector</a> </h3>

784

785 <p>The <dfn>universal selector</dfn>, written "asterisk"

786 (<code>*</code>), represents the qualified name of any element

787 type. It represents any single element in the document tree in any

788 namespace (including those without any declared namespace) if no

789 default namespace has been specified. If a default namespace has been

790 specified, see <a href="#univnmsp">Universal selector and

791 Namespaces</a> below.</p>

792

793 <p>If the universal selector is not the only component of a sequence

794 of simple selectors, the <code>*</code> may be omitted.</p>

795

796 <div class="example">

797 <p>Examples:</p>

798 <ul>

799 <li><code>*[hreflang\|=en]</code> and <code>[hreflang\|=en]</code> are equivalen t,</li>

800 <li><code>*.warning</code> and <code>.warning</code> are equivalent,</li>

801 <li><code>*#myid</code> and <code>#myid</code> are equivalent.</li>

802 </ul>

803 </div>

804

805 <p class="note"><strong>Note:</strong> it is recommended that the

806 <code>*</code>, representing the universal selector, not be

807 omitted.</p>

808

809 <h4><a name=univnmsp>6.2.1. Universal selector and namespaces</a></h4>

810

811 <p>The universal selector allows an optional namespace component. It

812 is used as follows:</p>

813

814 <dl>

815 <dt><code>ns\|*</code></dt>

816 <dd>all elements in namespace ns</dd>

817 <dt><code>\|</code></dt>

818 <dd>all elements</dd>

819 <dt><code>\|*</code></dt>

820 <dd>all elements without any declared namespace</dd>

821 <dt><code>*</code></dt>

822 <dd>if no default namespace has been specified, this is equivalent to \|.

823 Otherwise it is equivalent to ns\|* where ns is the default namespace.</dd>

824 </dl>

825

826 <p>A universal selector containing a namespace prefix that has not

827 been previously declared is an <a href="#Conformance">invalid</a>

828 selector. The mechanism for declaring a namespace prefix is left up

829 to the language implementing Selectors. In CSS, such a mechanism is

830 defined in the General Syntax module.</p>

831

832

833 <h3><a name=attribute-selectors>6.3. Attribute selectors</a></h3>

834

835 <p>Selectors allow the representation of an element's attributes. When

836 a selector is used as an expression to match against an element,

837 attribute selectors must be considered to match an element if that

838 element has an attribute that matches the attribute represented by the

839 attribute selector.</p>

840

841 <h4><a name=attribute-representation>6.3.1. Attribute presence and values

842 selectors</a></h4>

843

844 <p>CSS2 introduced four attribute selectors:</p>

845

846 <dl>

847 <dt><code>[att]</code>

848 <dd>Represents an element with the <code>att</code> attribute, whatever the va lue of

849 the attribute.</dd>

850 <dt><code>[att=val]</code></dt>

851 <dd>Represents an element with the <code>att</code> attribute whose value is e xactly

852 "val".</dd>

853 <dt><code>[att~=val]</code></dt>

854 <dd>Represents an element with the <code>att</code> attribute whose value is a <a

855 href="#whitespace">whitespace</a>-separated list of words, one of

856 which is exactly "val". If "val" contains whitespace, it will never

857 represent anything (since the words are <em>separated</em> by

858 spaces).</dd>

859 <dt><code>[att\|=val]</code>

860 <dd>Represents an element with the <code>att</code> attribute, its value eithe r

861 being exactly "val" or beginning with "val" immediately followed by

862 "-" (U+002D). This is primarily intended to allow language subcode

863 matches (e.g., the <code>hreflang</code> attribute on the

864 <code>link</code> element in HTML) as described in RFC 3066 (<a

865 href="#refsRFC3066">[RFC3066]</a>). For <code>lang</code> (or

866 <code>xml:lang</code>) language subcode matching, please see <a

867 href="#lang-pseudo">the <code>:lang</code> pseudo-class</a>.</dd>

868 </dl>

869

870 <p>Attribute values must be identifiers or strings. The

871 case-sensitivity of attribute names and values in selectors depends on

872 the document language.</p>

873

874 <div class="example">

875

876 <p>Examples:</p>

877

878 <p>The following attribute selector represents an <code>h1</code>

879 element that carries the <code>title</code> attribute, whatever its

880 value:</p>

881

882 <pre>h1[title]</pre>

883

884 <p>In the following example, the selector represents a

885 <code>span</code> element whose <code>class</code> attribute has

886 exactly the value "example":</p>

887

888 <pre>span[class="example"]</pre>

889

890 <p>Multiple attribute selectors can be used to represent several

891 attributes of an element, or several conditions on the same

892 attribute. Here, the selector represents a <code>span</code> element

893 whose <code>hello</code> attribute has exactly the value "Cleveland"

894 and whose <code>goodbye</code> attribute has exactly the value

895 "Columbus":</p>

896

897 <pre>span[hello="Cleveland"][goodbye="Columbus"]</pre>

898

899 <p>The following selectors illustrate the differences between "="

900 and "~=". The first selector will represent, for example, the value

901 "copyright copyleft copyeditor" on a <code>rel</code> attribute. The

902 second selector will only represent an <code>a</code> element with

903 an <code>href</code> attribute having the exact value

904 "http://www.w3.org/".</p>

905

906 <pre>a[rel~="copyright"]

907 a[href="http://www.w3.org/"]</pre>

908

909 <p>The following selector represents a <code>link</code> element

910 whose <code>hreflang</code> attribute is exactly "fr".</p>

911

912 <pre>link[hreflang=fr]</pre>

913

914 <p>The following selector represents a <code>link</code> element for

915 which the values of the <code>hreflang</code> attribute begins with

916 "en", including "en", "en-US", and "en-cockney":</p>

917

918 <pre>link[hreflang\|="en"]</pre>

919

920 <p>Similarly, the following selectors represents a

921 <code>DIALOGUE</code> element whenever it has one of two different

922 values for an attribute <code>character</code>:</p>

923

924 <pre>DIALOGUE[character=romeo]

925 DIALOGUE[character=juliet]</pre>

926

927 </div>

928

929 <h4><a name=attribute-substrings></a>6.3.2. Substring matching attribute

930 selectors</h4>

931

932 <p>Three additional attribute selectors are provided for matching

933 substrings in the value of an attribute:</p>

934

935 <dl>

936 <dt><code>[att^=val]</code></dt>

937 <dd>Represents an element with the <code>att</code> attribute whose value begi ns

938 with the prefix "val".</dd>

939 <dt><code>[att$=val]</code>

940 <dd>Represents an element with the <code>att</code> attribute whose value ends with

941 the suffix "val".</dd>

942 <dt><code>[att*=val]</code>

943 <dd>Represents an element with the <code>att</code> attribute whose value cont ains

944 at least one instance of the substring "val".</dd>

945 </dl>

946

947 <p>Attribute values must be identifiers or strings. The

948 case-sensitivity of attribute names in selectors depends on the

949 document language.</p>

950

951 <div class="example">

952 <p>Examples:</p>

953 <p>The following selector represents an HTML <code>object</code>, referencing a n

954 image:</p>

955 <pre>object[type^="image/"]</pre>

956 <p>The following selector represents an HTML anchor <code>a</code> with an

957 <code>href</code> attribute whose value ends with ".html".</p>

958 <pre>a[href$=".html"]</pre>

959 <p>The following selector represents an HTML paragraph with a <code>title</code >

960 attribute whose value contains the substring "hello"</p>

961 <pre>p[title*="hello"]</pre>

962 </div>

963

964 <h4><a name=attrnmsp>6.3.3. Attribute selectors and namespaces</a></h4>

965

966 <p>Attribute selectors allow an optional namespace component to the

967 attribute name. A namespace prefix that has been previously declared

968 may be prepended to the attribute name separated by the namespace

969 separator "vertical bar" (<code>\|</code>). In keeping with

970 the Namespaces in the XML recommendation, default namespaces do not

971 apply to attributes, therefore attribute selectors without a namespace

972 component apply only to attributes that have no declared namespace

973 (equivalent to "<code>\|attr</code>"). An asterisk may be used for the

974 namespace prefix indicating that the selector is to match all

975 attribute names without regard to the attribute's namespace.

976

977 <p>An attribute selector with an attribute name containing a namespace

978 prefix that has not been previously declared is an <a

979 href="#Conformance">invalid</a> selector. The mechanism for declaring

980 a namespace prefix is left up to the language implementing Selectors.

981 In CSS, such a mechanism is defined in the General Syntax module.

982

983 <div class="example">

984 <p>CSS examples:</p>

985 <pre>@namespace foo "http://www.example.com";

986 [foo\|att=val] { color: blue }

987 [*\|att] { color: yellow }

988 [\|att] { color: green }

989 [att] { color: green }</pre>

990

991 <p>The first rule will match only elements with the attribute

992 <code>att</code> in the "http://www.example.com" namespace with the

993 value "val".</p>

994

995 <p>The second rule will match only elements with the attribute

996 <code>att</code> regardless of the namespace of the attribute

997 (including no declared namespace).</p>

998

999 <p>The last two rules are equivalent and will match only elements

1000 with the attribute <code>att</code> where the attribute is not

1001 declared to be in a namespace.</p>

1002

1003 </div>

1004

1005 <h4><a name=def-values>6.3.4. Default attribute values in DTDs</a></h4>

1006

1007 <p>Attribute selectors represent explicitly set attribute values in

1008 the document tree. Default attribute values may be defined in a DTD or

1009 elsewhere, but cannot always be selected by attribute

1010 selectors. Selectors should be designed so that they work even if the

1011 default values are not included in the document tree.</p>

1012

1013 <p>More precisely, a UA is <em>not</em> required to read an "external

1014 subset" of the DTD but <em>is</em> required to look for default

1015 attribute values in the document's "internal subset." (See <a

1016 href="#refsXML10">[XML10]</a> for definitions of these subsets.)</p>

1017

1018 <p>A UA that recognizes an XML namespace <a

1019 href="#refsXMLNAMES">[XMLNAMES]</a> is not required to use its

1020 knowledge of that namespace to treat default attribute values as if

1021 they were present in the document. (For example, an XHTML UA is not

1022 required to use its built-in knowledge of the XHTML DTD.)</p>

1023

1024 <p class="note"><strong>Note:</strong> Typically, implementations

1025 choose to ignore external subsets.</p>

1026

1027 <div class="example">

1028 <p>Example:</p>

1029

1030 <p>Consider an element EXAMPLE with an attribute "notation" that has a

1031 default value of "decimal". The DTD fragment might be</p>

1032

1033 <pre class="dtd-example"><!ATTLIST EXAMPLE notation (decimal,octal) "decimal" ></pre>

1034

1035 <p>If the style sheet contains the rules</p>

1036

1037 <pre>EXAMPLE[notation=decimal] { /... default property settings .../ }

1038 EXAMPLE[notation=octal] { /... other settings.../ }</pre>

1039

1040 <p>the first rule will not match elements whose "notation" attribute

1041 is set by default, i.e. not set explicitly. To catch all cases, the

1042 attribute selector for the default value must be dropped:</p>

1043

1044 <pre>EXAMPLE { /... default property settings .../ }

1045 EXAMPLE[notation=octal] { /... other settings.../ }</pre>

1046

1047 <p>Here, because the selector <code>EXAMPLE[notation=octal]</code> is

1048 more specific than the tag

1049 selector alone, the style declarations in the second rule will override

1050 those in the first for elements that have a "notation" attribute value

1051 of "octal". Care has to be taken that all property declarations that

1052 are to apply only to the default case are overridden in the non-default

1053 cases' style rules.</p>

1054

1055 </div>

1056

1057 <h3><a name=class-html>6.4. Class selectors</a></h3>

1058

1059 <p>Working with HTML, authors may use the period (U+002E,

1060 <code>.</code>) notation as an alternative to the <code>~=</code>

1061 notation when representing the <code>class</code> attribute. Thus, for

1062 HTML, <code>div.value</code> and <code>div[class~=value]</code> have

1063 the same meaning. The attribute value must immediately follow the

1064 "period" (<code>.</code>).</p>

1065

1066 <p>UAs may apply selectors using the period (.) notation in XML

1067 documents if the UA has namespace-specific knowledge that allows it to

1068 determine which attribute is the "class" attribute for the

1069 respective namespace. One such example of namespace-specific knowledge

1070 is the prose in the specification for a particular namespace (e.g. SVG

1071 1.0 <a href="#refsSVG">[SVG]</a> describes the <a

1072 href="http://www.w3.org/TR/2001/PR-SVG-20010719/styling.html#ClassAttribute">SVG

1073 "class" attribute</a> and how a UA should interpret it, and

1074 similarly MathML 1.01 <a href="#refsMATH">[MATH]</a> describes the <a

1075 href="http://www.w3.org/1999/07/REC-MathML-19990707/chapter2.html#sec2.3.4">Math ML

1076 "class" attribute</a>.)</p>

1077

1078 <div class="example">

1079 <p>CSS examples:</p>

1080

1081 <p>We can assign style information to all elements with

1082 <code>class~="pastoral"</code> as follows:</p>

1083

1084 <pre>.pastoral { color: green } / all elements with class~=pastoral */</pre >

1085

1086 <p>or just</p>

1087

1088 <pre>.pastoral { color: green } /* all elements with class~=pastoral */</pre>

1089

1090 <p>The following assigns style only to H1 elements with

1091 <code>class~="pastoral"</code>:</p>

1092

1093 <pre>H1.pastoral { color: green } /* H1 elements with class~=pastoral */</pre >

1094

1095 <p>Given these rules, the first H1 instance below would not have

1096 green text, while the second would:</p>

1097

1098 <pre><H1>Not green</H1>

1099 <H1 class="pastoral">Very green</H1></pre>

1100

1101 </div>

1102

1103 <p>To represent a subset of "class" values, each value must be preceded

1104 by a ".", in any order.</P>

1105

1106 <div class="example">

1107

1108 <p>CSS example:</p>

1109

1110 <p>The following rule matches any P element whose "class" attribute

1111 has been assigned a list of <a

1112 href="#whitespace">whitespace</a>-separated values that includes

1113 "pastoral" and "marine":</p>

1114

1115 <pre>p.pastoral.marine { color: green }</pre>

1116

1117 <p>This rule matches when <code>class="pastoral blue aqua

1118 marine"</code> but does not match for <code>class="pastoral

1119 blue"</code>.</p>

1120

1121 </div>

1122

1123 <p class="note"><strong>Note:</strong> Because CSS gives considerable

1124 power to the "class" attribute, authors could conceivably design their

1125 own "document language" based on elements with almost no associated

1126 presentation (such as DIV and SPAN in HTML) and assigning style

1127 information through the "class" attribute. Authors should avoid this

1128 practice since the structural elements of a document language often

1129 have recognized and accepted meanings and author-defined classes may

1130 not.</p>

1131

1132 <p class="note"><strong>Note:</strong> If an element has multiple

1133 class attributes, their values must be concatenated with spaces

1134 between the values before searching for the class. As of this time the

1135 working group is not aware of any manner in which this situation can

1136 be reached, however, so this behavior is explicitly non-normative in

1137 this specification.</p>

1138

1139 <h3><a name=id-selectors>6.5. ID selectors</a></h3>

1140

1141 <p>Document languages may contain attributes that are declared to be

1142 of type ID. What makes attributes of type ID special is that no two

1143 such attributes can have the same value in a document, regardless of

1144 the type of the elements that carry them; whatever the document

1145 language, an ID typed attribute can be used to uniquely identify its

1146 element. In HTML all ID attributes are named "id"; XML applications

1147 may name ID attributes differently, but the same restriction

1148 applies.</p>

1149

1150 <p>An ID-typed attribute of a document language allows authors to

1151 assign an identifier to one element instance in the document tree. W3C

1152 ID selectors represent an element instance based on its identifier. An

1153 ID selector contains a "number sign" (U+0023,

1154 <code>#</code>) immediately followed by the ID value, which must be an

1155 identifier.</p>

1156

1157 <p>Selectors does not specify how a UA knows the ID-typed attribute of

1158 an element. The UA may, e.g., read a document's DTD, have the

1159 information hard-coded or ask the user.

1160

1161 <div class="example">

1162 <p>Examples:</p>

1163 <p>The following ID selector represents an <code>h1</code> element

1164 whose ID-typed attribute has the value "chapter1":</p>

1165 <pre>h1#chapter1</pre>

1166 <p>The following ID selector represents any element whose ID-typed

1167 attribute has the value "chapter1":</p>

1168 <pre>#chapter1</pre>

1169 <p>The following selector represents any element whose ID-typed

1170 attribute has the value "z98y".</p>

1171 <pre>*#z98y</pre>

1172 </div>

1173

1174 <p class="note"><strong>Note.</strong> In XML 1.0 <a

1175 href="#refsXML10">[XML10]</a>, the information about which attribute

1176 contains an element's IDs is contained in a DTD or a schema. When

1177 parsing XML, UAs do not always read the DTD, and thus may not know

1178 what the ID of an element is (though a UA may have namespace-specific

1179 knowledge that allows it to determine which attribute is the ID

1180 attribute for that namespace). If a style sheet designer knows or

1181 suspects that a UA may not know what the ID of an element is, he

1182 should use normal attribute selectors instead:

1183 <code>[name=p371]</code> instead of <code>#p371</code>. Elements in

1184 XML 1.0 documents without a DTD do not have IDs at all.</p>

1185

1186 <p>If an element has multiple ID attributes, all of them must be

1187 treated as IDs for that element for the purposes of the ID

1188 selector. Such a situation could be reached using mixtures of xml:id,

1189 DOM3 Core, XML DTDs, and namespace-specific knowledge.</p>

1190

1191 <h3><a name=pseudo-classes>6.6. Pseudo-classes</a></h3>

1192

1193 <p>The pseudo-class concept is introduced to permit selection based on

1194 information that lies outside of the document tree or that cannot be

1195 expressed using the other simple selectors.</p>

1196

1197 <p>A pseudo-class always consists of a "colon"

1198 (<code>:</code>) followed by the name of the pseudo-class and

1199 optionally by a value between parentheses.</p>

1200

1201 <p>Pseudo-classes are allowed in all sequences of simple selectors

1202 contained in a selector. Pseudo-classes are allowed anywhere in

1203 sequences of simple selectors, after the leading type selector or

1204 universal selector (possibly omitted). Pseudo-class names are

1205 case-insensitive. Some pseudo-classes are mutually exclusive, while

1206 others can be applied simultaneously to the same

1207 element. Pseudo-classes may be dynamic, in the sense that an element

1208 may acquire or lose a pseudo-class while a user interacts with the

1209 document.</p>

1210

1211

1212 <h4><a name=dynamic-pseudos>6.6.1. Dynamic pseudo-classes</a></h4>

1213

1214 <p>Dynamic pseudo-classes classify elements on characteristics other

1215 than their name, attributes, or content, in principle characteristics

1216 that cannot be deduced from the document tree.</p>

1217

1218 <p>Dynamic pseudo-classes do not appear in the document source or

1219 document tree.</p>

1220

1221

1222 <h5>The <a name=link>link pseudo-classes: :link and :visited</a></h5>

1223

1224 <p>User agents commonly display unvisited links differently from

1225 previously visited ones. Selectors

1226 provides the pseudo-classes <code>:link</code> and

1227 <code>:visited</code> to distinguish them:</p>

1228

1229 <ul>

1230 <li>The <code>:link</code> pseudo-class applies to links that have

1231 not yet been visited.</li>

1232 <li>The <code>:visited</code> pseudo-class applies once the link has

1233 been visited by the user. </li>

1234 </ul>

1235

1236 <p>After some amount of time, user agents may choose to return a

1237 visited link to the (unvisited) ':link' state.</p>

1238

1239 <p>The two states are mutually exclusive.</p>

1240

1241 <div class="example">

1242

1243 <p>Example:</p>

1244

1245 <p>The following selector represents links carrying class

1246 <code>external</code> and already visited:</p>

1247

1248 <pre>a.external:visited</pre>

1249

1250 </div>

1251

1252 <p class="note"><strong>Note:</strong> It is possible for style sheet

1253 authors to abuse the :link and :visited pseudo-classes to determine

1254 which sites a user has visited without the user's consent.

1255

1256 <p>UAs may therefore treat all links as unvisited links, or implement

1257 other measures to preserve the user's privacy while rendering visited

1258 and unvisited links differently.</p>

1259

1260 <h5>The <a name=useraction-pseudos>user action pseudo-classes

1261 :hover, :active, and :focus</a></h5>

1262

1263 <p>Interactive user agents sometimes change the rendering in response

1264 to user actions. Selectors provides

1265 three pseudo-classes for the selection of an element the user is

1266 acting on.</p>

1267

1268 <ul>

1269

1270 <li>The <code>:hover</code> pseudo-class applies while the user

1271 designates an element with a pointing device, but does not activate

1272 it. For example, a visual user agent could apply this pseudo-class

1273 when the cursor (mouse pointer) hovers over a box generated by the

1274 element. User agents not that do not support <a

1275 href="http://www.w3.org/TR/REC-CSS2/media.html#interactive-media-group">intera ctive

1276 media</a> do not have to support this pseudo-class. Some conforming

1277 user agents that support <a

1278 href="http://www.w3.org/TR/REC-CSS2/media.html#interactive-media-group">intera ctive

1279 media</a> may not be able to support this pseudo-class (e.g., a pen

1280 device that does not detect hovering).</li>

1281

1282 <li>The <code>:active</code> pseudo-class applies while an element

1283 is being activated by the user. For example, between the times the

1284 user presses the mouse button and releases it.</li>

1285

1286 <li>The <code>:focus</code> pseudo-class applies while an element

1287 has the focus (accepts keyboard or mouse events, or other forms of

1288 input). </li>

1289

1290 </ul>

1291

1292 <p>There may be document language or implementation specific limits on

1293 which elements can become <code>:active</code> or acquire

1294 <code>:focus</code>.</p>

1295

1296 <p>These pseudo-classes are not mutually exclusive. An element may

1297 match several pseudo-classes at the same time.</p>

1298

1299 <p>Selectors doesn't define if the parent of an element that is

1300 ':active' or ':hover' is also in that state.</p>

1301

1302 <div class="example">

1303 <p>Examples:</p>

1304 <pre>a:link /* unvisited links */

1305 a:visited /* visited links */

1306 a:hover /* user hovers */

1307 a:active /* active links */</pre>

1308 <p>An example of combining dynamic pseudo-classes:</p>

1309 <pre>a:focus

1310 a:focus:hover</pre>

1311 <p>The last selector matches <code>a</code> elements that are in

1312 the pseudo-class :focus and in the pseudo-class :hover.</p>

1313 </div>

1314

1315 <p class="note"><strong>Note:</strong> An element can be both ':visited'

1316 and ':active' (or ':link' and ':active').</p>

1317

1318 <h4><a name=target-pseudo>6.6.2. The target pseudo-class :target</a></h4>

1319

1320 <p>Some URIs refer to a location within a resource. This kind of URI

1321 ends with a "number sign" (#) followed by an anchor

1322 identifier (called the fragment identifier).</p>

1323

1324 <p>URIs with fragment identifiers link to a certain element within the

1325 document, known as the target element. For instance, here is a URI

1326 pointing to an anchor named <code>section_2</code> in an HTML

1327 document:</p>

1328

1329 <pre>http://example.com/html/top.html#section_2</pre>

1330

1331 <p>A target element can be represented by the <code>:target</code>

1332 pseudo-class. If the document's URI has no fragment identifier, then

1333 the document has no target element.</p>

1334

1335 <div class="example">

1336 <p>Example:</p>

1337 <pre>p.note:target</pre>

1338 <p>This selector represents a <code>p</code> element of class

1339 <code>note</code> that is the target element of the referring

1340 URI.</p>

1341 </div>

1342

1343 <div class="example">

1344 <p>CSS example:</p>

1345 <p>Here, the <code>:target</code> pseudo-class is used to make the

1346 target element red and place an image before it, if there is one:</p>

1347 <pre>*:target { color : red }

1348 *:target::before { content : url(target.png) }</pre>

1349 </div>

1350

1351 <h4><a name=lang-pseudo>6.6.3. The language pseudo-class :lang</a></h4>

1352

1353 <p>If the document language specifies how the human language of an

1354 element is determined, it is possible to write selectors that

1355 represent an element based on its language. For example, in HTML <a

1356 href="#refsHTML4">[HTML4]</a>, the language is determined by a

1357 combination of the <code>lang</code> attribute, the <code>meta</code>

1358 element, and possibly by information from the protocol (such as HTTP

1359 headers). XML uses an attribute called <code>xml:lang</code>, and

1360 there may be other document language-specific methods for determining

1361 the language.</p>

1362

1363 <p>The pseudo-class <code>:lang(C)</code> represents an element that

1364 is in language C. Whether an element is represented by a

1365 <code>:lang()</code> selector is based solely on the identifier C

1366 being either equal to, or a hyphen-separated substring of, the

1367 element's language value, in the same way as if performed by the <a

1368 href="#attribute-representation">'\|='</a> operator in attribute

1369 selectors. The identifier C does not have to be a valid language

1370 name.</p>

1371

1372 <p>C must not be empty. (If it is, the selector is invalid.)</p>

1373

1374 <p class="note"><strong>Note:</strong> It is recommended that

1375 documents and protocols indicate language using codes from RFC 3066 <a

1376 href="#refsRFC3066">[RFC3066]</a> or its successor, and by means of

1377 "xml:lang" attributes in the case of XML-based documents <a

1378 href="#refsXML10">[XML10]</a>. See <a

1379 href="http://www.w3.org/International/questions/qa-lang-2or3.html">

1380 "FAQ: Two-letter or three-letter language codes."</a></p>

1381

1382 <div class="example">

1383 <p>Examples:</p>

1384 <p>The two following selectors represent an HTML document that is in

1385 Belgian, French, or German. The two next selectors represent

1386 <code>q</code> quotations in an arbitrary element in Belgian, French,

1387 or German.</p>

1388 <pre>html:lang(fr-be)

1389 html:lang(de)

1390 :lang(fr-be) > q

1391 :lang(de) > q</pre>

1392 </div>

1393

1394 <h4><a name=UIstates>6.6.4. The UI element states pseudo-classes</a></h4>

1395

1396 <h5><a name=enableddisabled>The :enabled and :disabled pseudo-classes</a></h5>

1397

1398 <p>The <code>:enabled</code> pseudo-class allows authors to customize

1399 the look of user interface elements that are enabled — which the

1400 user can select or activate in some fashion (e.g. clicking on a button

1401 with a mouse). There is a need for such a pseudo-class because there

1402 is no way to programmatically specify the default appearance of say,

1403 an enabled <code>input</code> element without also specifying what it

1404 would look like when it was disabled.</p>

1405

1406 <p>Similar to <code>:enabled</code>, <code>:disabled</code> allows the

1407 author to specify precisely how a disabled or inactive user interface

1408 element should look.</p>

1409

1410 <p>Most elements will be neither enabled nor disabled. An element is

1411 enabled if the user can either activate it or transfer the focus to

1412 it. An element is disabled if it could be enabled, but the user cannot

1413 presently activate it or transfer focus to it.</p>

1414

1415

1416 <h5><a name=checked>The :checked pseudo-class</a></h5>

1417

1418 <p>Radio and checkbox elements can be toggled by the user. Some menu

1419 items are "checked" when the user selects them. When such elements are

1420 toggled "on" the <code>:checked</code> pseudo-class applies. The

1421 <code>:checked</code> pseudo-class initially applies to such elements

1422 that have the HTML4 <code>selected</code> and <code>checked</code>

1423 attributes as described in <a

1424 href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.2.1">Section

1425 17.2.1 of HTML4</a>, but of course the user can toggle "off" such

1426 elements in which case the <code>:checked</code> pseudo-class would no

1427 longer apply. While the <code>:checked</code> pseudo-class is dynamic

1428 in nature, and is altered by user action, since it can also be based

1429 on the presence of the semantic HTML4 <code>selected</code> and

1430 <code>checked</code> attributes, it applies to all media.

1431

1432

1433 <h5><a name=indeterminate>The :indeterminate pseudo-class</a></h5>

1434

1435 <div class="note">

1436

1437 <p>Radio and checkbox elements can be toggled by the user, but are

1438 sometimes in an indeterminate state, neither checked nor unchecked.

1439 This can be due to an element attribute, or DOM manipulation.</p>

1440

1441 <p>A future version of this specification may introduce an

1442 <code>:indeterminate</code> pseudo-class that applies to such elements.

1443 <!--While the <code>:indeterminate</code> pseudo-class is dynamic in

1444 nature, and is altered by user action, since it can also be based on

1445 the presence of an element attribute, it applies to all media.</p>

1446

1447 <p>Components of a radio-group initialized with no pre-selected choice

1448 are an example of :indeterminate state.--></p>

1449

1450 </div>

1451

1452

1453 <h4><a name=structural-pseudos>6.6.5. Structural pseudo-classes</a></h4>

1454

1455 <p>Selectors introduces the concept of <dfn>structural

1456 pseudo-classes</dfn> to permit selection based on extra information that lies in

1457 the document tree but cannot be represented by other simple selectors or

1458 combinators.

1459

1460 <p>Note that standalone pieces of PCDATA (text nodes in the DOM) are

1461 not counted when calculating the position of an element in the list of

1462 children of its parent. When calculating the position of an element in

1463 the list of children of its parent, the index numbering starts at 1.

1464

1465

1466 <h5><a name=root-pseudo>:root pseudo-class</a></h5>

1467

1468 <p>The <code>:root</code> pseudo-class represents an element that is

1469 the root of the document. In HTML 4, this is always the

1470 <code>HTML</code> element.

1471

1472

1473 <h5><a name=nth-child-pseudo>:nth-child() pseudo-class</a></h5>

1474

1475 <p>The

1476 <code>:nth-child(<var>a</var><code>n</code>+<var>b</var>)</code>

1477 pseudo-class notation represents an element that has

1478 <var>a</var><code>n</code>+<var>b</var>-1 siblings

1479 <strong>before</strong> it in the document tree, for a given positive

1480 integer or zero value of <code>n</code>, and has a parent element. In

1481 other words, this matches the <var>b</var>th child of an element after

1482 all the children have been split into groups of <var>a</var> elements

1483 each. For example, this allows the selectors to address every other

1484 row in a table, and could be used to alternate the color

1485 of paragraph text in a cycle of four. The <var>a</var> and

1486 <var>b</var> values must be zero, negative integers or positive

1487 integers. The index of the first child of an element is 1.

1488

1489 <p>In addition to this, <code>:nth-child()</code> can take

1490 '<code>odd</code>' and '<code>even</code>' as arguments instead.

1491 '<code>odd</code>' has the same signification as <code>2n+1</code>,

1492 and '<code>even</code>' has the same signification as <code>2n</code>.

1493

1494

1495 <div class="example">

1496 <p>Examples:</p>

1497 <pre>tr:nth-child(2n+1) /* represents every odd row of an HTML table */

1498 tr:nth-child(odd) /* same */

1499 tr:nth-child(2n) /* represents every even row of an HTML table */

1500 tr:nth-child(even) /* same */

1501

1502 /* Alternate paragraph colours in CSS */

1503 p:nth-child(4n+1) { color: navy; }

1504 p:nth-child(4n+2) { color: green; }

1505 p:nth-child(4n+3) { color: maroon; }

1506 p:nth-child(4n+4) { color: purple; }</pre>

1507 </div>

1508

1509 <p>When <var>a</var>=0, no repeating is used, so for example

1510 <code>:nth-child(0n+5)</code> matches only the fifth child. When

1511 <var>a</var>=0, the <var>a</var><code>n</code> part need not be

1512 included, so the syntax simplifies to

1513 <code>:nth-child(<var>b</var>)</code> and the last example simplifies

1514 to <code>:nth-child(5)</code>.

1515

1516 <div class="example">

1517 <p>Examples:</p>

1518 <pre>foo:nth-child(0n+1) /* represents an element foo, first child of its pare nt element */

1519 foo:nth-child(1) /* same */</pre>

1520 </div>

1521

1522 <p>When <var>a</var>=1, the number may be omitted from the rule.

1523

1524 <div class="example">

1525 <p>Examples:</p>

1526 <p>The following selectors are therefore equivalent:</p>

1527 <pre>bar:nth-child(1n+0) /* represents all bar elements, specificity (0,1,1) * /

1528 bar:nth-child(n+0) /* same */

1529 bar:nth-child(n) /* same */

1530 bar /* same but lower specificity (0,0,1) */</pre>

1531 </div>

1532

1533 <p>If <var>b</var>=0, then every <var>a</var>th element is picked. In

1534 such a case, the <var>b</var> part may be omitted.

1535

1536 <div class="example">

1537 <p>Examples:</p>

1538 <pre>tr:nth-child(2n+0) /* represents every even row of an HTML table */

1539 tr:nth-child(2n) /* same */</pre>

1540 </div>

1541

1542 <p>If both <var>a</var> and <var>b</var> are equal to zero, the

1543 pseudo-class represents no element in the document tree.</p>

1544

1545 <p>The value <var>a</var> can be negative, but only the positive

1546 values of <var>a</var><code>n</code>+<var>b</var>, for

1547 <code>n</code>≥0, may represent an element in the document

1548 tree.</p>

1549

1550 <div class="example">

1551 <p>Example:</p>

1552 <pre>html\|tr:nth-child(-n+6) /* represents the 6 first rows of XHTML tables */< /pre>

1553 </div>

1554

1555 <p>When the value <var>b</var> is negative, the "+" character in the

1556 expression must be removed (it is effectively replaced by the "-"

1557 character indicating the negative value of <var>b</var>).</p>

1558

1559 <div class="example">

1560 <p>Examples:</p>

1561 <pre>:nth-child(10n-1) /* represents the 9th, 19th, 29th, etc, element */

1562 :nth-child(10n+9) /* Same */

1563 :nth-child(10n+-1) /* Syntactically invalid, and would be ignored */</pre>

1564 </div>

1565

1566

1567 <h5><a name=nth-last-child-pseudo>:nth-last-child() pseudo-class</a></h5>

1568

1569 <p>The <code>:nth-last-child(<var>a</var>n+<var>b</var>)</code>

1570 pseudo-class notation represents an element that has

1571 <var>a</var><code>n</code>+<var>b</var>-1 siblings

1572 <strong>after</strong> it in the document tree, for a given positive

1573 integer or zero value of <code>n</code>, and has a parent element. See

1574 <code>:nth-child()</code> pseudo-class for the syntax of its argument.

1575 It also accepts the '<code>even</code>' and '<code>odd</code>' values

1576 as arguments.

1577

1578

1579 <div class="example">

1580 <p>Examples:</p>

1581 <pre>tr:nth-last-child(-n+2) /* represents the two last rows of an HTML table */

1582

1583 foo:nth-last-child(odd) /* represents all odd foo elements in their parent el ement,

1584 counting from the last one */</pre>

1585 </div>

1586

1587

1588 <h5><a name=nth-of-type-pseudo>:nth-of-type() pseudo-class</a></h5>

1589

1590 <p>The <code>:nth-of-type(<var>a</var>n+<var>b</var>)</code>

1591 pseudo-class notation represents an element that has

1592 <var>a</var><code>n</code>+<var>b</var>-1 siblings with the same

1593 element name <strong>before</strong> it in the document tree, for a

1594 given zero or positive integer value of <code>n</code>, and has a

1595 parent element. In other words, this matches the <var>b</var>th child

1596 of that type after all the children of that type have been split into

1597 groups of a elements each. See <code>:nth-child()</code> pseudo-class

1598 for the syntax of its argument. It also accepts the

1599 '<code>even</code>' and '<code>odd</code>' values.

1600

1601

1602 <div class="example">

1603 <p>CSS example:</p>

1604 <p>This allows an author to alternate the position of floated images:</p>

1605 <pre>img:nth-of-type(2n+1) { float: right; }

1606 img:nth-of-type(2n) { float: left; }</pre>

1607 </div>

1608

1609

1610 <h5><a name=nth-last-of-type-pseudo>:nth-last-of-type() pseudo-class</a></h5>

1611

1612 <p>The <code>:nth-last-of-type(<var>a</var>n+<var>b</var>)</code>

1613 pseudo-class notation represents an element that has

1614 <var>a</var><code>n</code>+<var>b</var>-1 siblings with the same

1615 element name <strong>after</strong> it in the document tree, for a

1616 given zero or positive integer value of <code>n</code>, and has a

1617 parent element. See <code>:nth-child()</code> pseudo-class for the

1618 syntax of its argument. It also accepts the '<code>even</code>' and '<code>odd</ code>' values.

1619

1620

1621 <div class="example">

1622 <p>Example:</p>

1623 <p>To represent all <code>h2</code> children of an XHTML

1624 <code>body</code> except the first and last, one could use the

1625 following selector:</p>

1626 <pre>body > h2:nth-of-type(n+2):nth-last-of-type(n+2)</pre>

1627 <p>In this case, one could also use <code>:not()</code>, although the

1628 selector ends up being just as long:</p>

1629 <pre>body > h2:not(:first-of-type):not(:last-of-type)</pre>

1630 </div>

1631

1632

1633 <h5><a name=first-child-pseudo>:first-child pseudo-class</a></h5>

1634

1635 <p>Same as <code>:nth-child(1)</code>. The <code>:first-child</code> pseudo-clas s

1636 represents an element that is the first child of some other element.

1637

1638

1639 <div class="example">

1640 <p>Examples:</p>

1641 <p>The following selector represents a <code>p</code> element that is

1642 the first child of a <code>div</code> element:</p>

1643 <pre>div > p:first-child</pre>

1644 <p>This selector can represent the <code>p</code> inside the

1645 <code>div</code> of the following fragment:</p>

1646 <pre><p> The last P before the note.</p>

1647 <div class="note">

1648 <p> The first P inside the note.</p>

1649 </div></pre>but cannot represent the second <code>p</code> in the followin g

1650 fragment:

1651 <pre><p> The last P before the note.</p>

1652 <div class="note">

1653 <h2> Note </h2>

1654 <p> The first P inside the note.</p>

1655 </div></pre>

1656 <p>The following two selectors are usually equivalent:</p>

1657 <pre>* > a:first-child /* a is first child of any element */

1658 a:first-child /* Same (assuming a is not the root element) */</pre>

1659 </div>

1660

1661 <h5><a name=last-child-pseudo>:last-child pseudo-class</a></h5>

1662

1663 <p>Same as <code>:nth-last-child(1)</code>. The <code>:last-child</code> pseudo- class

1664 represents an element that is the last child of some other element.

1665

1666 <div class="example">

1667 <p>Example:</p>

1668 <p>The following selector represents a list item <code>li</code> that

1669 is the last child of an ordered list <code>ol</code>.

1670 <pre>ol > li:last-child</pre>

1671 </div>

1672

1673 <h5><a name=first-of-type-pseudo>:first-of-type pseudo-class</a></h5>

1674

1675 <p>Same as <code>:nth-of-type(1)</code>. The <code>:first-of-type</code> pseudo- class

1676 represents an element that is the first sibling of its type in the list of

1677 children of its parent element.

1678

1679 <div class="example">

1680 <p>Example:</p>

1681 <p>The following selector represents a definition title

1682 <code>dt</code> inside a definition list <code>dl</code>, this

1683 <code>dt</code> being the first of its type in the list of children of

1684 its parent element.</p>

1685 <pre>dl dt:first-of-type</pre>

1686 <p>It is a valid description for the first two <code>dt</code>

1687 elements in the following example but not for the third one:</p>

1688 <pre><dl>

1689 <dt>gigogne</dt>

1690 <dd>

1691 <dl>

1692 <dt>fusée</dt>

1693 <dd>multistage rocket</dd>

1694 <dt>table</dt>

1695 <dd>nest of tables</dd>

1696 </dl>

1697 </dd>

1698 </dl></pre>

1699 </div>

1700

1701 <h5><a name=last-of-type-pseudo>:last-of-type pseudo-class</a></h5>

1702

1703 <p>Same as <code>:nth-last-of-type(1)</code>. The

1704 <code>:last-of-type</code> pseudo-class represents an element that is

1705 the last sibling of its type in the list of children of its parent

1706 element.</p>

1707

1708 <div class="example">

1709 <p>Example:</p>

1710 <p>The following selector represents the last data cell

1711 <code>td</code> of a table row.</p>

1712 <pre>tr > td:last-of-type</pre>

1713 </div>

1714

1715 <h5><a name=only-child-pseudo>:only-child pseudo-class</a></h5>

1716

1717 <p>Represents an element that has a parent element and whose parent

1718 element has no other element children. Same as

1719 <code>:first-child:last-child</code> or

1720 <code>:nth-child(1):nth-last-child(1)</code>, but with a lower

1721 specificity.</p>

1722

1723 <h5><a name=only-of-type-pseudo>:only-of-type pseudo-class</a></h5>

1724

1725 <p>Represents an element that has a parent element and whose parent

1726 element has no other element children with the same element name. Same

1727 as <code>:first-of-type:last-of-type</code> or

1728 <code>:nth-of-type(1):nth-last-of-type(1)</code>, but with a lower

1729 specificity.</p>

1730

1731

1732 <h5><a name=empty-pseudo></a>:empty pseudo-class</h5>

1733

1734 <p>The <code>:empty</code> pseudo-class represents an element that has

1735 no children at all. In terms of the DOM, only element nodes and text

1736 nodes (including CDATA nodes and entity references) whose data has a

1737 non-zero length must be considered as affecting emptiness; comments,

1738 PIs, and other nodes must not affect whether an element is considered

1739 empty or not.</p>

1740

1741 <div class="example">

1742 <p>Examples:</p>

1743 <p><code>p:empty</code> is a valid representation of the following fragment:</p >

1744 <pre><p></p></pre>

1745 <p><code>foo:empty</code> is not a valid representation for the

1746 following fragments:</p>

1747 <pre><foo>bar</foo></pre>

1748 <pre><foo><bar>bla</bar></foo></pre>

1749 <pre><foo>this is not <bar>:empty</bar></foo></pre>

1750 </div>

1751

1752 <h4><a name=content-selectors>6.6.6. Blank</a></h4> <!-- It's the Return of Appe ndix H!!! Run away! -->

1753

1754 <p>This section intentionally left blank.</p>

1755 <!-- (used to be :contains()) -->

1756

1757 <h4><a name=negation></a>6.6.7. The negation pseudo-class</h4>

1758

1759 <p>The negation pseudo-class, <code>:not(<var>X</var>)</code>, is a

1760 functional notation taking a <a href="#simple-selectors-dfn">simple

1761 selector</a> (excluding the negation pseudo-class itself and

1762 pseudo-elements) as an argument. It represents an element that is not

1763 represented by the argument.

1764

1765 <!-- pseudo-elements are not simple selectors, so the above paragraph

1766 may be a bit confusing -->

1767

1768 <div class="example">

1769 <p>Examples:</p>

1770 <p>The following CSS selector matches all <code>button</code>

1771 elements in an HTML document that are not disabled.</p>

1772 <pre>button:not([DISABLED])</pre>

1773 <p>The following selector represents all but <code>FOO</code>

1774 elements.</p>

1775 <pre>*:not(FOO)</pre>

1776 <p>The following group of selectors represents all HTML elements

1777 except links.</p>

1778 <pre>html\|*:not(:link):not(:visited)</pre>

1779 </div>

1780

1781 <p>Default namespace declarations do not affect the argument of the

1782 negation pseudo-class unless the argument is a universal selector or a

1783 type selector.</p>

1784

1785 <div class="example">

1786 <p>Examples:</p>

1787 <p>Assuming that the default namespace is bound to

1788 "http://example.com/", the following selector represents all

1789 elements that are not in that namespace:</p>

1790 <pre>\|:not(*)</pre>

1791 <p>The following CSS selector matches any element being hovered,

1792 regardless of its namespace. In particular, it is not limited to

1793 only matching elements in the default namespace that are not being

1794 hovered, and elements not in the default namespace don't match the

1795 rule when they <em>are</em> being hovered.</p>

1796 <pre>\|:not(:hover)</pre>

1797 </div>

1798

1799 <p class="note"><strong>Note</strong>: the :not() pseudo allows

1800 useless selectors to be written. For instance <code>:not(\|)</code>,

1801 which represents no element at all, or <code>foo:not(bar)</code>,

1802 which is equivalent to <code>foo</code> but with a higher

1803 specificity.</p>

1804

1805 <h3><a name=pseudo-elements>7. Pseudo-elements</a></h3>

1806

1807 <p>Pseudo-elements create abstractions about the document tree beyond

1808 those specified by the document language. For instance, document

1809 languages do not offer mechanisms to access the first letter or first

1810 line of an element's content. Pseudo-elements allow designers to refer

1811 to this otherwise inaccessible information. Pseudo-elements may also

1812 provide designers a way to refer to content that does not exist in the

1813 source document (e.g., the <code>::before</code> and

1814 <code>::after</code> pseudo-elements give access to generated

1815 content).</p>

1816

1817 <p>A pseudo-element is made of two colons (<code>::</code>) followed

1818 by the name of the pseudo-element.</p>

1819

1820 <p>This <code>::</code> notation is introduced by the current document

1821 in order to establish a discrimination between pseudo-classes and

1822 pseudo-elements. For compatibility with existing style sheets, user

1823 agents must also accept the previous one-colon notation for

1824 pseudo-elements introduced in CSS levels 1 and 2 (namely,

1825 <code>:first-line</code>, <code>:first-letter</code>,

1826 <code>:before</code> and <code>:after</code>). This compatibility is

1827 not allowed for the new pseudo-elements introduced in CSS level 3.</p>

1828

1829 <p>Only one pseudo-element may appear per selector, and if present it

1830 must appear after the sequence of simple selectors that represents the

1831 <a href="#subject">subjects</a> of the selector. <span class="note">A

1832 future version of this specification may allow multiple

1833 pesudo-elements per selector.</span></p>

1834

1835 <h4><a name=first-line>7.1. The ::first-line pseudo-element</a></h4>

1836

1837 <p>The <code>::first-line</code> pseudo-element describes the contents

1838 of the first formatted line of an element.

1839

1840 <div class="example">

1841 <p>CSS example:</p>

1842 <pre>p::first-line { text-transform: uppercase }</pre>

1843 <p>The above rule means "change the letters of the first line of every

1844 paragraph to uppercase".</p>

1845 </div>

1846

1847 <p>The selector <code>p::first-line</code> does not match any real

1848 HTML element. It does match a pseudo-element that conforming user

1849 agents will insert at the beginning of every paragraph.</p>

1850

1851 <p>Note that the length of the first line depends on a number of

1852 factors, including the width of the page, the font size, etc. Thus,

1853 an ordinary HTML paragraph such as:</p>

1854

1855 <pre>

1856 <P>This is a somewhat long HTML

1857 paragraph that will be broken into several

1858 lines. The first line will be identified

1859 by a fictional tag sequence. The other lines

1860 will be treated as ordinary lines in the

1861 paragraph.</P>

1862 </pre>

1863

1864 <p>the lines of which happen to be broken as follows:

1865

1866 <pre>

1867 THIS IS A SOMEWHAT LONG HTML PARAGRAPH THAT

1868 will be broken into several lines. The first

1869 line will be identified by a fictional tag

1870 sequence. The other lines will be treated as

1871 ordinary lines in the paragraph.

1872 </pre>

1873

1874 <p>This paragraph might be "rewritten" by user agents to include the

1875 <em>fictional tag sequence</em> for <code>::first-line</code>. This

1876 fictional tag sequence helps to show how properties are inherited.</p>

1877

1878 <pre>

1879 <P><b><P::first-line></b> This is a somewhat long HTML

1880 paragraph that <b></P::first-line></b> will be broken into several

1881 lines. The first line will be identified

1882 by a fictional tag sequence. The other lines

1883 will be treated as ordinary lines in the

1884 paragraph.</P>

1885 </pre>

1886

1887 <p>If a pseudo-element breaks up a real element, the desired effect

1888 can often be described by a fictional tag sequence that closes and

1889 then re-opens the element. Thus, if we mark up the previous paragraph

1890 with a <code>span</code> element:</p>

1891

1892 <pre>

1893 <P><b><SPAN class="test"></b> This is a somewhat long HTML

1894 paragraph that will be broken into several

1895 lines.<b></SPAN></b> The first line will be identified

1896 by a fictional tag sequence. The other lines

1897 will be treated as ordinary lines in the

1898 paragraph.</P>

1899 </pre>

1900

1901 <p>the user agent could simulate start and end tags for

1902 <code>span</code> when inserting the fictional tag sequence for

1903 <code>::first-line</code>.

1904

1905 <pre>

1906 <P><P::first-line><b><SPAN class="test"></b> This is a

1907 somewhat long HTML

1908 paragraph that will <b></SPAN></b></P::first-line><b><SPAN class= "test"></b> be

1909 broken into several

1910 lines.<b></SPAN></b> The first line will be identified

1911 by a fictional tag sequence. The other lines

1912 will be treated as ordinary lines in the

1913 paragraph.</P>

1914 </pre>

1915

1916 <p>In CSS, the <code>::first-line</code> pseudo-element can only be

1917 attached to a block-level element, an inline-block, a table-caption,

1918 or a table-cell.</p>

1919

1920 <p><a name="first-formatted-line"></a>The "first formatted line" of an

1921 element may occur inside a

1922 block-level descendant in the same flow (i.e., a block-level

1923 descendant that is not positioned and not a float). E.g., the first

1924 line of the <code>div</code> in <code><DIV><P>This

1925 line...</P>&lt/DIV></code> is the first line of the <code>p</code> (assuming

1926 that both <code>p</code> and <code>div</code> are block-level).

1927

1928 <p>The first line of a table-cell or inline-block cannot be the first

1929 formatted line of an ancestor element. Thus, in <code><DIV><P

1930 STYLE="display: inline-block">Hello<BR>Goodbye</P>

1931 etcetera</DIV></code> the first formatted line of the

1932 <code>div</code> is not the line "Hello".

1933

1934 <p class="note">Note that the first line of the <code>p</code> in this

1935 fragment: <code><p&gt<br>First...</code> doesn't contain any

1936 letters (assuming the default style for <code>br</code> in HTML

1937 4). The word "First" is not on the first formatted line.

1938

1939 <p>A UA should act as if the fictional start tags of the

1940 <code>::first-line</code> pseudo-elements were nested just inside the

1941 innermost enclosing block-level element. (Since CSS1 and CSS2 were

1942 silent on this case, authors should not rely on this behavior.) Here

1943 is an example. The fictional tag sequence for</p>

1944

1945 <pre>

1946 <DIV>

1947 <P>First paragraph</P>

1948 <P>Second paragraph</P>

1949 </DIV>

1950 </pre>

1951

1952 <p>is</p>

1953

1954 <pre>

1955 <DIV>

1956 <P><DIV::first-line><P::first-line>First paragraph</P::first-line> </DIV::first-line></P>

1957 <P><P::first-line>Second paragraph</P::first-line></P>

1958 </DIV>

1959 </pre>

1960

1961 <p>The <code>::first-line</code> pseudo-element is similar to an

1962 inline-level element, but with certain restrictions. In CSS, the

1963 following properties apply to a <code>::first-line</code>

1964 pseudo-element: font properties, color property, background

1965 properties, 'word-spacing', 'letter-spacing', 'text-decoration',

1966 'vertical-align', 'text-transform', 'line-height'. UAs may apply other

1967 properties as well.</p>

1968

1969

1970 <h4><a name=first-letter>7.2. The ::first-letter pseudo-element</a></h4>

1971

1972 <p>The <code>::first-letter</code> pseudo-element represents the first

1973 letter of the first line of a block, if it is not preceded by any

1974 other content (such as images or inline tables) on its line. The

1975 ::first-letter pseudo-element may be used for "initial caps" and "drop

1976 caps", which are common typographical effects. This type of initial

1977 letter is similar to an inline-level element if its 'float' property

1978 is 'none'; otherwise, it is similar to a floated element.</p>

1979

1980 <p>In CSS, these are the properties that apply to <code>::first-letter</code>

1981 pseudo-elements: font properties, 'text-decoration', 'text-transform',

1982 'letter-spacing', 'word-spacing' (when appropriate), 'line-height',

1983 'float', 'vertical-align' (only if 'float' is 'none'), margin

1984 properties, padding properties, border properties, color property,

1985 background properties. UAs may apply other properties as well. To

1986 allow UAs to render a typographically correct drop cap or initial cap,

1987 the UA may choose a line-height, width and height based on the shape

1988 of the letter, unlike for normal elements.</p>

1989

1990 <div class="example">

1991 <p>Example:</p>

1992 <p>This example shows a possible rendering of an initial cap. Note

1993 that the 'line-height' that is inherited by the <code>::first-letter</code>

1994 pseudo-element is 1.1, but the UA in this example has computed the

1995 height of the first letter differently, so that it doesn't cause any

1996 unnecessary space between the first two lines. Also note that the

1997 fictional start tag of the first letter is inside the <span>span</span>, and thu s

1998 the font weight of the first letter is normal, not bold as the <span>span</span> :

1999 <pre>

2000 p { line-height: 1.1 }

2001 p::first-letter { font-size: 3em; font-weight: normal }

2002 span { font-weight: bold }

2003 ...

2004 <p><span>Het hemelsche</span> gerecht heeft zich ten lange lesten<br >

2005 Erbarremt over my en mijn benaeuwde vesten<br>

2006 En arme burgery, en op mijn volcx gebed<br>

2007 En dagelix geschrey de bange stad ontzet.

2008 </pre>

2009 <div class="figure">

2010 <p><img src="initial-cap.png" alt="Image illustrating the ::first-letter pseudo- element">

2011 </div>

2012 </div>

2013

2014 <div class="example">

2015 <p>The following CSS will make a drop cap initial letter span about two lines:</ p>

2016

2017 <pre>

2018 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">

2019 <HTML>

2020 <HEAD>

2021 <TITLE>Drop cap initial letter</TITLE>

2022 <STYLE type="text/css">

2023 P { font-size: 12pt; line-height: 1.2 }

2024 P::first-letter { font-size: 200%; font-weight: bold; float: left }

2025 SPAN { text-transform: uppercase }

2026 </STYLE>

2027 </HEAD>

2028 <BODY>

2029 <P><SPAN>The first</SPAN> few words of an article

2030 in The Economist.</P>

2031 </BODY>

2032 </HTML>

2033 </pre>

2034

2035 <p>This example might be formatted as follows:</p>

2036

2037 <div class="figure">

2038 <P><img src="first-letter.gif" alt="Image illustrating the combined effect of th e ::first-letter and ::first-line pseudo-elements"></p>

2039 </div>

2040

2041 <p>The <span class="index-inst" title="fictional tag

2042 sequence">fictional tag sequence</span> is:</p>

2043

2044 <pre>

2045 <P>

2046 <SPAN>

2047 <P::first-letter>

2048 T

2049 </P::first-letter>he first

2050 </SPAN>

2051 few words of an article in the Economist.

2052 </P>

2053 </pre>

2054

2055 <p>Note that the <code>::first-letter</code> pseudo-element tags abut

2056 the content (i.e., the initial character), while the ::first-line

2057 pseudo-element start tag is inserted right after the start tag of the

2058 block element.</p> </div>

2059

2060 <p>In order to achieve traditional drop caps formatting, user agents

2061 may approximate font sizes, for example to align baselines. Also, the

2062 glyph outline may be taken into account when formatting.</p>

2063

2064 <p>Punctuation (i.e, characters defined in Unicode in the "open" (Ps),

2065 "close" (Pe), "initial" (Pi). "final" (Pf) and "other" (Po)

2066 punctuation classes), that precedes or follows the first letter should

2067 be included. <a href="#refsUNICODE">[UNICODE]</a></p>

2068

2069 <div class="figure">

2070 <P><img src="first-letter2.gif" alt="Quotes that precede the

2071 first letter should be included."></p>

2072 </div>

2073

2074 <p>The <code>::first-letter</code> also applies if the first letter is

2075 in fact a digit, e.g., the "6" in "67 million dollars is a lot of

2076 money."</p>

2077

2078 <p>In CSS, the <code>::first-letter</code> pseudo-element applies to

2079 block, list-item, table-cell, table-caption, and inline-block

2080 elements. <span class="note">A future version of this specification

2081 may allow this pesudo-element to apply to more element

2082 types.</span></p>

2083

2084 <p>The <code>::first-letter</code> pseudo-element can be used with all

2085 such elements that contain text, or that have a descendant in the same

2086 flow that contains text. A UA should act as if the fictional start tag

2087 of the ::first-letter pseudo-element is just before the first text of

2088 the element, even if that first text is in a descendant.</p>

2089

2090 <div class="example">

2091 <p>Example:</p>

2092 <p>The fictional tag sequence for this HTMLfragment:

2093 <pre><div>

2094 <p>The first text.</pre>

2095 <p>is:

2096 <pre><div>

2097 <p><div::first-letter><p::first-letter>T</...></...>he first text .</pre>

2098 </div>

2099

2100 <p>The first letter of a table-cell or inline-block cannot be the

2101 first letter of an ancestor element. Thus, in <code><DIV><P

2102 STYLE="display: inline-block">Hello<BR>Goodbye</P>

2103 etcetera</DIV></code> the first letter of the <code>div</code> is not the

2104 letter "H". In fact, the <code>div</code> doesn't have a first letter.

2105

2106 <p>The first letter must occur on the <a

2107 href="#first-formatted-line">first formatted line.</a> For example, in

2108 this fragment: <code><p&gt<br>First...</code> the first line

2109 doesn't contain any letters and <code>::first-letter</code> doesn't

2110 match anything (assuming the default style for <code>br</code> in HTML

2111 4). In particular, it does not match the "F" of "First."

2112

2113 <p>In CSS, if an element is a list item ('display: list-item'), the

2114 <code>::first-letter</code> applies to the first letter in the

2115 principal box after the marker. UAs may ignore

2116 <code>::first-letter</code> on list items with 'list-style-position:

2117 inside'. If an element has <code>::before</code> or

2118 <code>::after</code> content, the <code>::first-letter</code> applies

2119 to the first letter of the element <em>including</em> that content.

2120

2121 <div class="example">

2122 <p>Example:</p>

2123 <p>After the rule 'p::before {content: "Note: "}', the selector

2124 'p::first-letter' matches the "N" of "Note".</p>

2125 </div>

2126

2127 <p>Some languages may have specific rules about how to treat certain

2128 letter combinations. In Dutch, for example, if the letter combination

2129 "ij" appears at the beginning of a word, both letters should be

2130 considered within the <code>::first-letter</code> pseudo-element.

2131

2132 <p>If the letters that would form the ::first-letter are not in the

2133 same element, such as "'T" in <code><p>'<em>T...</code>, the UA

2134 may create a ::first-letter pseudo-element from one of the elements,

2135 both elements, or simply not create a pseudo-element.</p>

2136

2137 <p>Similarly, if the first letter(s) of the block are not at the start

2138 of the line (for example due to bidirectional reordering), then the UA

2139 need not create the pseudo-element(s).

2140

2141 <div class="example">

2142 <p>Example:</p>

2143 <p><a name="overlapping-example">The following example</a> illustrates

2144 how overlapping pseudo-elements may interact. The first letter of

2145 each P element will be green with a font size of '24pt'. The rest of

2146 the first formatted line will be 'blue' while the rest of the

2147 paragraph will be 'red'.</p>

2148

2149 <pre>p { color: red; font-size: 12pt }

2150 p::first-letter { color: green; font-size: 200% }

2151 p::first-line { color: blue }

2152

2153 <P>Some text that ends up on two lines</P></pre>

2154

2155 <p>Assuming that a line break will occur before the word "ends", the

2156 <span class="index-inst" title="fictional tag sequence">fictional tag

2157 sequence</span> for this fragment might be:</p>

2158

2159 <pre><P>

2160 <P::first-line>

2161 <P::first-letter>

2162 S

2163 </P::first-letter>ome text that

2164 </P::first-line>

2165 ends up on two lines

2166 </P></pre>

2167

2168 <p>Note that the <code>::first-letter</code> element is inside the <code>::first -line</code>

2169 element. Properties set on <code>::first-line</code> are inherited by

2170 <code>::first-letter</code>, but are overridden if the same property is set on

2171 <code>::first-letter</code>.</p>

2172 </div>

2173

2174

2175 <h4><a name=UIfragments>7.3.</a> <a name=selection>The ::selection pseudo-elemen t</a></h4>

2176

2177 <p>The <code>::selection</code> pseudo-element applies to the portion

2178 of a document that has been highlighted by the user. This also

2179 applies, for example, to selected text within an editable text

2180 field. This pseudo-element should not be confused with the <code><a

2181 href="#checked">:checked</a></code> pseudo-class (which used to be

2182 named <code>:selected</code>)

2183

2184 <p>Although the <code>::selection</code> pseudo-element is dynamic in

2185 nature, and is altered by user action, it is reasonable to expect that

2186 when a UA re-renders to a static medium (such as a printed page, see

2187 <a href="#refsCSS21">[CSS21]</a>) which was originally rendered to a

2188 dynamic medium (like screen), the UA may wish to transfer the current

2189 <code>::selection</code> state to that other medium, and have all the

2190 appropriate formatting and rendering take effect as well. This is not

2191 required — UAs may omit the <code>::selection</code>

2192 pseudo-element for static media.

2193

2194 <p>These are the CSS properties that apply to <code>::selection</code>

2195 pseudo-elements: color, background, cursor (optional), outline

2196 (optional). The computed value of the 'background-image' property on

2197 <code>::selection</code> may be ignored.

2198

2199

2200 <h4><a name=gen-content>7.4. The ::before and ::after pseudo-elements</a></h4>

2201

2202 <p>The <code>::before</code> and <code>::after</code> pseudo-elements

2203 can be used to describe generated content before or after an element's

2204 content. They are explained in CSS 2.1 <a

2205 href="#refsCSS21">[CSS21]</a>.</p>

2206

2207 <p>When the <code>::first-letter</code> and <code>::first-line</code>

2208 pseudo-elements are combined with <code>::before</code> and

2209 <code>::after</code>, they apply to the first letter or line of the

2210 element including the inserted text.</p>

2211

2212 <h2><a name=combinators>8. Combinators</a></h2>

2213

2214 <h3><a name=descendant-combinators>8.1. Descendant combinator</a></h3>

2215

2216 <p>At times, authors may want selectors to describe an element that is

2217 the descendant of another element in the document tree (e.g., "an

2218 <code>EM</code> element that is contained within an <code>H1</code>

2219 element"). Descendant combinators express such a relationship. A

2220 descendant combinator is <a href="#whitespace">white space</a> that

2221 separates two sequences of simple selectors. A selector of the form

2222 "<code>A B</code>" represents an element <code>B</code> that is an

2223 arbitrary descendant of some ancestor element <code>A</code>.

2224

2225 <div class="example">

2226 <p>Examples:</p>

2227 <p>For example, consider the following selector:</p>

2228 <pre>h1 em</pre>

2229 <p>It represents an <code>em</code> element being the descendant of

2230 an <code>h1</code> element. It is a correct and valid, but partial,

2231 description of the following fragment:</p>

2232 <pre><h1>This <span class="myclass">headline

2233 is <em>very</em> important</span></h1></pre>

2234 <p>The following selector:</p>

2235 <pre>div * p</pre>

2236 <p>represents a <code>p</code> element that is a grandchild or later

2237 descendant of a <code>div</code> element. Note the whitespace on

2238 either side of the "*" is not part of the universal selector; the

2239 whitespace is a combinator indicating that the DIV must be the

2240 ancestor of some element, and that that element must be an ancestor

2241 of the P.</p>

2242 <p>The following selector, which combines descendant combinators and

2243 <a href="#attribute-selectors">attribute selectors</a>, represents an

2244 element that (1) has the <code>href</code> attribute set and (2) is

2245 inside a <code>p</code> that is itself inside a <code>div</code>:</p>

2246 <pre>div p *[href]</pre>

2247 </div>

2248

2249 <h3><a name=child-combinators>8.2. Child combinators</a></h3>

2250

2251 <p>A <dfn>child combinator</dfn> describes a childhood relationship

2252 between two elements. A child combinator is made of the

2253 "greater-than sign" (<code>></code>) character and

2254 separates two sequences of simple selectors.

2255

2256

2257 <div class="example">

2258 <p>Examples:</p>

2259 <p>The following selector represents a <code>p</code> element that is

2260 child of <code>body</code>:</p>

2261 <pre>body > p</pre>

2262 <p>The following example combines descendant combinators and child

2263 combinators.</p>

2264 <pre>div ol>li p</pre><!-- LEAVE THOSE SPACES OUT! see below -->

2265 <p>It represents a <code>p</code> element that is a descendant of an

2266 <code>li</code> element; the <code>li</code> element must be the

2267 child of an <code>ol</code> element; the <code>ol</code> element must

2268 be a descendant of a <code>div</code>. Notice that the optional white

2269 space around the ">" combinator has been left out.</p>

2270 </div>

2271

2272 <p>For information on selecting the first child of an element, please

2273 see the section on the <code><a

2274 href="#structural-pseudos">:first-child</a></code> pseudo-class

2275 above.</p>

2276

2277 <h3><a name=sibling-combinators>8.3. Sibling combinators</a></h3>

2278

2279 <p>There are two different sibling combinators: the adjacent sibling

2280 combinator and the general sibling combinator. In both cases,

2281 non-element nodes (e.g. text between elements) are ignored when

2282 considering adjacency of elements.</p>

2283

2284 <h4><a name=adjacent-sibling-combinators>8.3.1. Adjacent sibling combinator</a>< /h4>

2285

2286 <p>The adjacent sibling combinator is made of the "plus

2287 sign" (U+002B, <code>+</code>) character that separates two

2288 sequences of simple selectors. The elements represented by the two

2289 sequences share the same parent in the document tree and the element

2290 represented by the first sequence immediately precedes the element

2291 represented by the second one.</p>

2292

2293 <div class="example">

2294 <p>Examples:</p>

2295 <p>The following selector represents a <code>p</code> element

2296 immediately following a <code>math</code> element:</p>

2297 <pre>math + p</pre>

2298 <p>The following selector is conceptually similar to the one in the

2299 previous example, except that it adds an attribute selector — it

2300 adds a constraint to the <code>h1</code> element, that it must have

2301 <code>class="opener"</code>:</p>

2302 <pre>h1.opener + h2</pre>

2303 </div>

2304

2305

2306 <h4><a name=general-sibling-combinators>8.3.2. General sibling combinator</a></h 4>

2307

2308 <p>The general sibling combinator is made of the "tilde"

2309 (U+007E, <code>~</code>) character that separates two sequences of

2310 simple selectors. The elements represented by the two sequences share

2311 the same parent in the document tree and the element represented by

2312 the first sequence precedes (not necessarily immediately) the element

2313 represented by the second one.</p>

2314

2315 <div class="example">

2316 <p>Example:</p>

2317 <pre>h1 ~ pre</pre>

2318 <p>represents a <code>pre</code> element following an <code>h1</code>. It

2319 is a correct and valid, but partial, description of:</p>

2320 <pre><h1>Definition of the function a</h1>

2321 <p>Function a(x) has to be applied to all figures in the table.</p>

2322 <pre>function a(x) = 12x/13.5</pre></pre>

2323 </div>

2324

2325 <h2><a name=specificity>9. Calculating a selector's specificity</a></h2>

2326

2327 <p>A selector's specificity is calculated as follows:</p>

2328

2329 <ul>

2330 <li>count the number of ID selectors in the selector (= a)</li>

2331 <li>count the number of class selectors, attributes selectors, and pseudo-clas ses in the selector (= b)</li>

2332 <li>count the number of element names in the selector (= c)</li>

2333 <li>ignore pseudo-elements</li>

2334 </ul>

2335

2336 <p>Selectors inside <a href="#negation">the negation pseudo-class</a>

2337 are counted like any other, but the negation itself does not count as

2338 a pseudo-class.</p>

2339

2340 <p>Concatenating the three numbers a-b-c (in a number system with a

2341 large base) gives the specificity.</p>

2342

2343 <div class="example">

2344 <p>Examples:</p>

2345 <pre>* /* a=0 b=0 c=0 -> specificity = 0 */

2346 LI /* a=0 b=0 c=1 -> specificity = 1 */

2347 UL LI /* a=0 b=0 c=2 -> specificity = 2 */

2348 UL OL+LI /* a=0 b=0 c=3 -> specificity = 3 */

2349 H1 + [REL=up] / a=0 b=1 c=1 -> specificity = 11 */

2350 UL OL LI.red /* a=0 b=1 c=3 -> specificity = 13 */

2351 LI.red.level /* a=0 b=2 c=1 -> specificity = 21 */

2352 #x34y /* a=1 b=0 c=0 -> specificity = 100 */

2353 #s12:not(FOO) /* a=1 b=0 c=1 -> specificity = 101 */

2354 </pre>

2355 </div>

2356

2357 <p class="note"><strong>Note:</strong> the specificity of the styles

2358 specified in an HTML <code>style</code> attribute is described in CSS

2359 2.1. <a href="#refsCSS21">[CSS21]</a>.</p>

2360

2361 <h2><a name=w3cselgrammar>10. The grammar of Selectors</a></h2>

2362

2363 <h3><a name=grammar>10.1. Grammar</a></h3>

2364

2365 <p>The grammar below defines the syntax of Selectors. It is globally

2366 LL(1) and can be locally LL(2) (but note that most UA's should not use

2367 it directly, since it doesn't express the parsing conventions). The

2368 format of the productions is optimized for human consumption and some

2369 shorthand notations beyond Yacc (see <a href="#refsYACC">[YACC]</a>)

2370 are used:</p>

2371

2372 <ul>

2373 <li><b>*</b>: 0 or more

2374 <li><b>+</b>: 1 or more

2375 <li><b>?</b>: 0 or 1

2376 <li><b>\|</b>: separates alternatives

2377 <li><b>[ ]</b>: grouping </li>

2378 </ul>

2379

2380 <p>The productions are:</p>

2381

2382 <pre>selectors_group

2383 : selector [ COMMA S* selector ]*

2384 ;

2385

2386 selector

2387 : simple_selector_sequence [ combinator simple_selector_sequence ]*

2388 ;

2389

2390 combinator

2391 /* combinators can be surrounded by white space */

2392 : PLUS S* \| GREATER S* \| TILDE S* \| S+

2393 ;

2394

2395 simple_selector_sequence

2396 : [ type_selector \| universal ]

2397 [ HASH \| class \| attrib \| pseudo \| negation ]*

2398 \| [ HASH \| class \| attrib \| pseudo \| negation ]+

2399 ;

2400

2401 type_selector

2402 : [ namespace_prefix ]? element_name

2403 ;

2404

2405 namespace_prefix

2406 : [ IDENT \| '*' ]? '\|'

2407 ;

2408

2409 element_name

2410 : IDENT

2411 ;

2412

2413 universal

2414 : [ namespace_prefix ]? '*'

2415 ;

2416

2417 class

2418 : '.' IDENT

2419 ;

2420

2421 attrib

2422 : '[' S* [ namespace_prefix ]? IDENT S*

2423 [ [ PREFIXMATCH \|

2424 SUFFIXMATCH \|

2425 SUBSTRINGMATCH \|

2426 '=' \|

2427 INCLUDES \|

2428 DASHMATCH ] S* [ IDENT \| STRING ] S*

2429 ]? ']'

2430 ;

2431

2432 pseudo

2433 /* '::' starts a pseudo-element, ':' a pseudo-class */

2434 /* Exceptions: :first-line, :first-letter, :before and :after. */

2435 /* Note that pseudo-elements are restricted to one per selector and */

2436 /* occur only in the last simple_selector_sequence. */

2437 : ':' ':'? [ IDENT \| functional_pseudo ]

2438 ;

2439

2440 functional_pseudo

2441 : FUNCTION S* expression ')'

2442 ;

2443

2444 expression

2445 /* In CSS3, the expressions are identifiers, strings, */

2446 /* or of the form "an+b" */

2447 : [ [ PLUS \| '-' \| DIMENSION \| NUMBER \| STRING \| IDENT ] S* ]+

2448 ;

2449

2450 negation

2451 : NOT S* negation_arg S* ')'

2452 ;

2453

2454 negation_arg

2455 : type_selector \| universal \| HASH \| class \| attrib \| pseudo

2456 ;</pre>

2457

2458

2459 <h3><a name=lex>10.2. Lexical scanner</a></h3>

2460

2461 <p>The following is the <a name=x3>tokenizer</a>, written in Flex (see

2462 <a href="#refsFLEX">[FLEX]</a>) notation. The tokenizer is

2463 case-insensitive.</p>

2464

2465 <p>The two occurrences of "\377" represent the highest character

2466 number that current versions of Flex can deal with (decimal 255). They

2467 should be read as "\4177777" (decimal 1114111), which is the highest

2468 possible code point in Unicode/ISO-10646. <a

2469 href="#refsUNICODE">[UNICODE]</a></p>

2470

2471 <pre>%option case-insensitive

2472

2473 ident [-]?{nmstart}{nmchar}*

2474 name {nmchar}+

2475 nmstart [_a-z]\|{nonascii}\|{escape}

2476 nonascii [^\0-\177]

2477 unicode \\[0-9a-f]{1,6}(\r\n\|[ \n\r\t\f])?

2478 escape {unicode}\|\\[^\n\r\f0-9a-f]

2479 nmchar [_a-z0-9-]\|{nonascii}\|{escape}

2480 num [0-9]+\|[0-9]*\.[0-9]+

2481 string {string1}\|{string2}

2482 string1 \"([^\n\r\f\\"]\|\\{nl}\|{nonascii}\|{escape})*\"

2483 string2 \'([^\n\r\f\\']\|\\{nl}\|{nonascii}\|{escape})*\'

2484 invalid {invalid1}\|{invalid2}

2485 invalid1 \"([^\n\r\f\\"]\|\\{nl}\|{nonascii}\|{escape})*

2486 invalid2 \'([^\n\r\f\\']\|\\{nl}\|{nonascii}\|{escape})*

2487 nl \n\|\r\n\|\r\|\f

2488 w [ \t\r\n\f]*

2489

2490 %%

2491

2492 [ \t\r\n\f]+ return S;

2493

2494 "~=" return INCLUDES;

2495 "\|=" return DASHMATCH;

2496 "^=" return PREFIXMATCH;

2497 "$=" return SUFFIXMATCH;

2498 "*=" return SUBSTRINGMATCH;

2499 {ident} return IDENT;

2500 {string} return STRING;

2501 {ident}"(" return FUNCTION;

2502 {num} return NUMBER;

2503 "#"{name} return HASH;

2504 {w}"+" return PLUS;

2505 {w}">" return GREATER;

2506 {w}"," return COMMA;

2507 {w}"~" return TILDE;

2508 ":not(" return NOT;

2509 @{ident} return ATKEYWORD;

2510 {invalid} return INVALID;

2511 {num}% return PERCENTAGE;

2512 {num}{ident} return DIMENSION;

2513 "<!--" return CDO;

2514 "-->" return CDC;

2515

2516 "url("{w}{string}{w}")" return URI;

2517 "url("{w}([!#$%&-~]\|{nonascii}\|{escape}){w}")" return URI;

2518 U\+[0-9a-f?]{1,6}(-[0-9a-f]{1,6})? return UNICODE_RANGE;

2519

2520 \/\[^]\+([^/][^]\+)\/ / ignore comments */

2521

2522 . return *yytext;</pre>

2523

2524

2525

2526 <h2><a name=downlevel>11. Namespaces and down-level clients</a></h2>

2527

2528 <p>An important issue is the interaction of CSS selectors with XML

2529 documents in web clients that were produced prior to this

2530 document. Unfortunately, due to the fact that namespaces must be

2531 matched based on the URI which identifies the namespace, not the

2532 namespace prefix, some mechanism is required to identify namespaces in

2533 CSS by their URI as well. Without such a mechanism, it is impossible

2534 to construct a CSS style sheet which will properly match selectors in

2535 all cases against a random set of XML documents. However, given

2536 complete knowledge of the XML document to which a style sheet is to be

2537 applied, and a limited use of namespaces within the XML document, it

2538 is possible to construct a style sheet in which selectors would match

2539 elements and attributes correctly.</p>

2540

2541 <p>It should be noted that a down-level CSS client will (if it

2542 properly conforms to CSS forward compatible parsing rules) ignore all

2543 <code>@namespace</code> at-rules, as well as all style rules that make

2544 use of namespace qualified element type or attribute selectors. The

2545 syntax of delimiting namespace prefixes in CSS was deliberately chosen

2546 so that down-level CSS clients would ignore the style rules rather

2547 than possibly match them incorrectly.</p>

2548

2549 <p>The use of default namespaces in CSS makes it possible to write

2550 element type selectors that will function in both namespace aware CSS

2551 clients as well as down-level clients. It should be noted that

2552 down-level clients may incorrectly match selectors against XML

2553 elements in other namespaces.</p>

2554

2555 <p>The following are scenarios and examples in which it is possible to

2556 construct style sheets which would function properly in web clients

2557 that do not implement this proposal.</p>

2558

2559 <ol>

2560 <li>

2561

2562 <p>The XML document does not use namespaces.</p>

2563

2564 <ul>

2565

2566 <li>In this case, it is obviously not necessary to declare or use

2567 namespaces in the style sheet. Standard CSS element type and

2568 attribute selectors will function adequately in a down-level

2569 client.</li>

2570

2571 <li>In a CSS namespace aware client, the default behavior of

2572 element selectors matching without regard to namespace will

2573 function properly against all elements, since no namespaces are

2574 present. However, the use of specific element type selectors that

2575 match only elements that have no namespace ("<code>\|name</code>")

2576 will guarantee that selectors will match only XML elements that do

2577 not have a declared namespace. </li>

2578

2579 </ul>

2580

2581 </li>

2582

2583 <li>

2584

2585 <p>The XML document defines a single, default namespace used

2586 throughout the document. No namespace prefixes are used in element

2587 names.</p>

2588

2589 <ul>

2590

2591 <li>In this case, a down-level client will function as if

2592 namespaces were not used in the XML document at all. Standard CSS

2593 element type and attribute selectors will match against all

2594 elements. </li>

2595

2596 </ul>

2597

2598 </li>

2599

2600 <li>

2601

2602 <p>The XML document does <b>not</b> use a default namespace, all

2603 namespace prefixes used are known to the style sheet author, and

2604 there is a direct mapping between namespace prefixes and namespace

2605 URIs. (A given prefix may only be mapped to one namespace URI

2606 throughout the XML document; there may be multiple prefixes mapped

2607 to the same URI).</p>

2608

2609 <ul>

2610

2611 <li>In this case, the down-level client will view and match

2612 element type and attribute selectors based on their fully

2613 qualified name, not the local part as outlined in the <a

2614 href="#typenmsp">Type selectors and Namespaces</a> section. CSS

2615 selectors may be declared using an escaped colon "<code>\:</code>"

2616 to describe the fully qualified names, e.g.

2617 "<code>html\:h1</code>" will match

2618 <code><html:h1></code>. Selectors using the qualified name

2619 will only match XML elements that use the same prefix. Other

2620 namespace prefixes used in the XML that are mapped to the same URI

2621 will not match as expected unless additional CSS style rules are

2622 declared for them.</li>

2623

2624 <li>Note that selectors declared in this fashion will

2625 <em>only</em> match in down-level clients. A CSS namespace aware

2626 client will match element type and attribute selectors based on

2627 the name's local part. Selectors declared with the fully

2628 qualified name will not match (unless there is no namespace prefix

2629 in the fully qualified name).</li>

2630

2631 </ul>

2632

2633 </li>

2634

2635 </ol>

2636

2637 <p>In other scenarios: when the namespace prefixes used in the XML are

2638 not known in advance by the style sheet author; or a combination of

2639 elements with no namespace are used in conjunction with elements using

2640 a default namespace; or the same namespace prefix is mapped to

2641 <em>different</em> namespace URIs within the same document, or in

2642 different documents; it is impossible to construct a CSS style sheet

2643 that will function properly against all elements in those documents,

2644 unless, the style sheet is written using a namespace URI syntax (as

2645 outlined in this document or similar) and the document is processed by

2646 a CSS and XML namespace aware client.</p>

2647

2648 <h2><a name=profiling>12. Profiles</a></h2>

2649

2650 <p>Each specification using Selectors must define the subset of W3C

2651 Selectors it allows and excludes, and describe the local meaning of

2652 all the components of that subset.</p>

2653

2654 <p>Non normative examples:

2655

2656 <div class="profile">

2657 <table class="tprofile">

2658 <tbody>

2659 <tr>

2660 <th class="title" colspan=2>Selectors profile</th></tr>

2661 <tr>

2662 <th>Specification</th>

2663 <td>CSS level 1</td></tr>

2664 <tr>

2665 <th>Accepts</th>

2666 <td>type selectors<br>class selectors<br>ID selectors<br>:link,

2667 :visited and :active pseudo-classes<br>descendant combinator

2668 <br>::first-line and ::first-letter pseudo-elements</td></tr>

2669 <tr>

2670 <th>Excludes</th>

2671 <td>

2672

2673 <p>universal selector<br>attribute selectors<br>:hover and :focus

2674 pseudo-classes<br>:target pseudo-class<br>:lang() pseudo-class<br>all UI

2675 element states pseudo-classes<br>all structural

2676 pseudo-classes<br>negation pseudo-class<br>all

2677 UI element fragments pseudo-elements<br>::before and ::after

2678 pseudo-elements<br>child combinators<br>sibling combinators

2679

2680 <p>namespaces</td></tr>

2681 <tr>

2682 <th>Extra constraints</th>

2683 <td>only one class selector allowed per sequence of simple

2684 selectors</td></tr></tbody></table><br><br>

2685 <table class="tprofile">

2686 <tbody>

2687 <tr>

2688 <th class="title" colspan=2>Selectors profile</th></tr>

2689 <tr>

2690 <th>Specification</th>

2691 <td>CSS level 2</td></tr>

2692 <tr>

2693 <th>Accepts</th>

2694 <td>type selectors<br>universal selector<br>attribute presence and

2695 values selectors<br>class selectors<br>ID selectors<br>:link, :visited,

2696 :active, :hover, :focus, :lang() and :first-child pseudo-classes

2697 <br>descendant combinator<br>child combinator<br>adjacent sibling

2698 combinator<br>::first-line and ::first-letter pseudo-elements<br>::before

2699 and ::after pseudo-elements</td></tr>

2700 <tr>

2701 <th>Excludes</th>

2702 <td>

2703

2704 <p>content selectors<br>substring matching attribute

2705 selectors<br>:target pseudo-classes<br>all UI element

2706 states pseudo-classes<br>all structural pseudo-classes other

2707 than :first-child<br>negation pseudo-class<br>all UI element

2708 fragments pseudo-elements<br>general sibling combinators

2709

2710 <p>namespaces</td></tr>

2711 <tr>

2712 <th>Extra constraints</th>

2713 <td>more than one class selector per sequence of simple selectors (CSS1

2714 constraint) allowed</td></tr></tbody></table>

2715

2716 <p>In CSS, selectors express pattern matching rules that determine which style

2717 rules apply to elements in the document tree.

2718

2719 <p>The following selector (CSS level 2) will <b>match</b> all anchors <code>a</c ode>

2720 with attribute <code>name</code> set inside a section 1 header <code>h1</code>:

2721 <pre>h1 a[name]</pre>

2722

2723 <p>All CSS declarations attached to such a selector are applied to elements

2724 matching it. </div>

2725

2726 <div class="profile">

2727 <table class="tprofile">

2728 <tbody>

2729 <tr>

2730 <th class="title" colspan=2>Selectors profile</th></tr>

2731 <tr>

2732 <th>Specification</th>

2733 <td>STTS 3</td>

2734 </tr>

2735 <tr>

2736 <th>Accepts</th>

2737 <td>

2738

2739 <p>type selectors<br>universal selectors<br>attribute selectors<br>class

2740 selectors<br>ID selectors<br>all structural pseudo-classes<br>

2741 all combinators

2742

2743 <p>namespaces</td></tr>

2744 <tr>

2745 <th>Excludes</th>

2746 <td>non-accepted pseudo-classes<br>pseudo-elements<br></td></tr>

2747 <tr>

2748 <th>Extra constraints</th>

2749 <td>some selectors and combinators are not allowed in fragment

2750 descriptions on the right side of STTS declarations.</td></tr></tbody></ta ble>

2751 <form>

2752 <input type="text" name="test10"/>

2753 <input type="text" name="foo"/>

2754 <input type="text" name="foo"/>

2755 <input type="text" name="foo"/>

2756 <input type="text" name="foo"/>

2757 <input type="text" name="foo"/>

2758 <input type="text" name="foo"/>

2759 <input type="text" name="foo"/>

2760 <input type="text" name="foo"/>

2761 <input type="text" name="foo"/>

2762 <input type="text" name="foo"/>

2763 <input type="text" name="foo"/>

2764 <input type="text" name="foo"/>

2765 <input type="text" name="foo"/>

2766 <input type="text" name="foo"/>

2767 <input type="text" name="foo"/>

2768 <input type="text" name="foo"/>

2769 <input type="text" name="foo"/>

2770 <input type="text" name="foo"/>

2771 <input type="text" name="foo"/>

2772 <input type="text" name="foo"/>

2773 <input type="text" name="foo"/>

2774 <input type="text" name="foo"/>

2775 <input type="text" name="foo"/>

2776 <input type="text" name="foo"/>

2777 </form>

2778

2779 <p>Selectors can be used in STTS 3 in two different

2780 manners:

2781 <ol>

2782 <li>a selection mechanism equivalent to CSS selection mechanism: declarations

2783 attached to a given selector are applied to elements matching that selector,

2784 <li>fragment descriptions that appear on the right side of declarations.

2785 </li></ol></div>

2786

2787 <h2><a name=Conformance></a>13. Conformance and requirements</h2>

2788

2789 <p>This section defines conformance with the present specification only.

2790

2791 <p>The inability of a user agent to implement part of this specification due to

2792 the limitations of a particular device (e.g., non interactive user agents will

2793 probably not implement dynamic pseudo-classes because they make no sense without

2794 interactivity) does not imply non-conformance.

2795

2796 <p>All specifications reusing Selectors must contain a <a

2797 href="#profiling">Profile</a> listing the

2798 subset of Selectors it accepts or excludes, and describing the constraints

2799 it adds to the current specification.

2800

2801 <p>Invalidity is caused by a parsing error, e.g. an unrecognized token or a toke n

2802 which is not allowed at the current parsing point.

2803

2804 <p>User agents must observe the rules for handling parsing errors:

2805 <ul>

2806 <li>a simple selector containing an undeclared namespace prefix is invalid</li >

2807 <li>a selector containing an invalid simple selector, an invalid combinator

2808 or an invalid token is invalid. </li>

2809 <li>a group of selectors containing an invalid selector is invalid.</li>

2810 </ul>

2811

2812 <p class="foo test10 bar">Specifications reusing Selectors must define how to ha ndle parsing

2813 errors. (In the case of CSS, the entire rule in which the selector is

2814 used is dropped.)</p>

2815

2816 <!-- Apparently all these references are out of date:

2817 <p>Implementations of this specification must behave as

2818 "recipients of text data" as defined by <a href="#refsCWWW">[CWWW]</a>

2819 when parsing selectors and attempting matches. (In particular,

2820 implementations must assume the data is normalized and must not

2821 normalize it.) Normative rules for matching strings are defined in

2822 <a href="#refsCWWW">[CWWW]</a> and <a

2823 href="#refsUNICODE">[UNICODE]</a> and apply to implementations of this

2824 specification.</p>-->

2825

2826 <h2><a name=Tests></a>14. Tests</h2>

2827

2828 <p>This specification has <a

2829 href="http://www.w3.org/Style/CSS/Test/CSS3/Selectors/current/">a test

2830 suite</a> allowing user agents to verify their basic conformance to

2831 the specification. This test suite does not pretend to be exhaustive

2832 and does not cover all possible combined cases of Selectors.</p>

2833

2834 <h2><a name=ACKS></a>15. Acknowledgements</h2>

2835

2836 <p>The CSS working group would like to thank everyone who has sent

2837 comments on this specification over the years.</p>

2838

2839 <p>The working group would like to extend special thanks to Donna

2840 McManus, Justin Baker, Joel Sklar, and Molly Ives Brower who perfermed

2841 the final editorial review.</p>

2842

2843 <h2><a name=references>16. References</a></h2>

2844

2845 <dl class="refs">

2846

2847 <dt>[CSS1]

2848 <dd><a name=refsCSS1></a> Bert Bos, Håkon Wium Lie; "<cite>Cascading Sty le Sheets, level 1</cite>", W3C Recommendation, 17 Dec 1996, revised 11 Jan 1999

2849 <dd>(<code><a href="http://www.w3.org/TR/REC-CSS1">http://www.w3.org/TR/REC-CS S1</a></code>)

2850

2851 <dt>[CSS21]

2852 <dd><a name=refsCSS21></a> Bert Bos, Tantek Çelik, Ian Hickson, H&aring ;kon Wium Lie, editors; "<cite>Cascading Style Sheets, level 2 revision 1</cite> ", W3C Working Draft, 13 June 2005

2853 <dd>(<code><a href="http://www.w3.org/TR/CSS21">http://www.w3.org/TR/CSS21</a> </code>)

2854

2855 <dt>[CWWW]

2856 <dd><a name=refsCWWW></a> Martin J. Dürst, François Yergeau, Misha Wolf, Asmus Freytag, Tex Texin, editors; "<cite>Character Model for the World W ide Web</cite>", W3C Recommendation, 15 February 2005

2857 <dd>(<code><a href="http://www.w3.org/TR/charmod/">http://www.w3.org/TR/charmo d/</a></code>)

2858

2859 <dt>[FLEX]

2860 <dd><a name="refsFLEX"></a> "<cite>Flex: The Lexical Scanner Generator</cite>" , Version 2.3.7, ISBN 1882114213

2861

2862 <dt>[HTML4]

2863 <dd><a name="refsHTML4"></a> Dave Ragget, Arnaud Le Hors, Ian Jacobs, editors; "<cite>HTML 4.01 Specification</cite>", W3C Recommendation, 24 December 1999

2864 <dd>(<a href="http://www.w3.org/TR/html4/"><code>http://www.w3.org/TR/html4/</ code></a>)

2865

2866 <dt>[MATH]

2867 <dd><a name="refsMATH"></a> Patrick Ion, Robert Miner, editors; "<cite>Mathema tical Markup Language (MathML) 1.01</cite>", W3C Recommendation, revision of 7 J uly 1999

2868 <dd>(<code><a href="http://www.w3.org/TR/REC-MathML/">http://www.w3.org/TR/REC -MathML/</a></code>)

2869

2870 <dt>[RFC3066]

2871 <dd><a name="refsRFC3066"></a> H. Alvestrand; "<cite>Tags for the Identificati on of Languages</cite>", Request for Comments 3066, January 2001

2872 <dd>(<a href="http://www.ietf.org/rfc/rfc3066.txt"><code>http://www.ietf.org/r fc/rfc3066.txt</code></a>)

2873

2874 <dt>[STTS]

2875 <dd><a name=refsSTTS></a> Daniel Glazman; "<cite>Simple Tree Transformation Sh eets 3</cite>", Electricité de France, submission to the W3C, 11 November 1998

2876 <dd>(<code><a href="http://www.w3.org/TR/NOTE-STTS3">http://www.w3.org/TR/NOTE -STTS3</a></code>)

2877

2878 <dt>[SVG]

2879 <dd><a name="refsSVG"></a> Jon Ferraiolo, 藤沢淳, Dean Jack son, editors; "<cite>Scalable Vector Graphics (SVG) 1.1 Specification</cite>", W 3C Recommendation, 14 January 2003

2880 <dd>(<code><a href="http://www.w3.org/TR/SVG/">http://www.w3.org/TR/SVG/</a></ code>)

2881

2882 <dt>[UNICODE]</dt>

2883 <dd><a name="refsUNICODE"></a> <cite><a

2884 href="http://www.unicode.org/versions/Unicode4.1.0/">The Unicode Standard, Ve rsion 4.1</a></cite>, The Unicode Consortium. Boston, MA, Addison-Wesley, March 2005. ISBN 0-321-18578-1, as amended by <a href="http://www.unicode.org/versions /Unicode4.0.1/">Unicode 4.0.1</a> and <a href="http://www.unicode.org/versions/U nicode4.1.0/">Unicode 4.1.0</a>.

2885 <dd>(<code><a href="http://www.unicode.org/versions/">http://www.unicode.org/v ersions/</a></code>)</dd>

2886

2887 <dt>[XML10]

2888 <dd><a name="refsXML10"></a> Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, Eve Maler, François Yergeau, editors; "<cite>Extensible Markup Language (XML ) 1.0 (Third Edition)</cite>", W3C Recommendation, 4 February 2004

2889 <dd>(<a href="http://www.w3.org/TR/REC-xml/"><code>http://www.w3.org/TR/REC-xm l/</code></a>)

2890

2891 <dt>[XMLNAMES]

2892 <dd><a name="refsXMLNAMES"></a> Tim Bray, Dave Hollander, Andrew Layman, edito rs; "<cite>Namespaces in XML</cite>", W3C Recommendation, 14 January 1999

2893 <dd>(<a href="http://www.w3.org/TR/REC-xml-names/"><code>http://www.w3.org/TR/ REC-xml-names/</code></a>)

2894

2895 <dt>[YACC]

2896 <dd><a name="refsYACC"></a> S. C. Johnson; "<cite>YACC — Yet another com piler compiler</cite>", Technical Report, Murray Hill, 1975

2897

2898 </dl>

2899 </body>

2900 </html>

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