- From: poot <cvsmail@w3.org>
- Date: Tue, 16 Aug 2011 20:44:09 -0400
- To: public-html-diffs@w3.org
hixie: Explain requirements (whatwg r6479)
http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.5180&r2=1.5181&f=h
http://html5.org/tools/web-apps-tracker?from=6478&to=6479
===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.5180
retrieving revision 1.5181
diff -u -d -r1.5180 -r1.5181
--- Overview.html 16 Aug 2011 06:06:35 -0000 1.5180
+++ Overview.html 17 Aug 2011 00:43:14 -0000 1.5181
@@ -321,7 +321,7 @@
<h1>HTML5</h1>
<h2 class="no-num no-toc" id="a-vocabulary-and-associated-apis-for-html-and-xhtml">A vocabulary and associated APIs for HTML and XHTML</h2>
- <h2 class="no-num no-toc" id="editor-s-draft-16-august-2011">Editor's Draft 16 August 2011</h2>
+ <h2 class="no-num no-toc" id="editor-s-draft-17-august-2011">Editor's Draft 17 August 2011</h2>
<dl><dt>Latest Published Version:</dt>
<dd><a href="http://www.w3.org/TR/html5/">http://www.w3.org/TR/html5/</a></dd>
<dt>Latest Editor's Draft:</dt>
@@ -467,7 +467,7 @@
Group</a> is the W3C working group responsible for this
specification's progress along the W3C Recommendation
track.
- This specification is the 16 August 2011 Editor's Draft.
+ This specification is the 17 August 2011 Editor's Draft.
</p><!-- UNDER NO CIRCUMSTANCES IS THE PRECEDING PARAGRAPH TO BE REMOVED OR EDITED WITHOUT TALKING TO IAN FIRST --><p>Work on this specification is also done at the <a href="http://www.whatwg.org/">WHATWG</a>. The W3C HTML working group
actively pursues convergence with the WHATWG, as required by the <a href="http://www.w3.org/2007/03/HTML-WG-charter">W3C HTML working
group charter</a>.</p><!-- UNDER NO CIRCUMSTANCES IS THE FOLLOWING PARAGRAPH TO BE REMOVED OR EDITED WITHOUT TALKING TO IAN FIRST --><p>This document was produced by a group operating under the <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5
@@ -8281,11 +8281,49 @@
(by this specification) to have certain meanings (semantics). For
example, the <code><a href="#the-ol-element">ol</a></code> element represents an ordered list, and
the <code title="attr-lang"><a href="#attr-lang">lang</a></code> attribute represents the
- language of the content.<p>Authors must not use elements, attributes, or attribute values
- for purposes other than their appropriate intended semantic
- purpose. Authors must not use elements, attributes, or attribute
- values that are not permitted by this specification or <a href="#other-applicable-specifications">other
- applicable specifications</a>.<div class="example">
+ language of the content.<p>These definitions allow HTML processors, such as Web browsers or
+ search engines, to present and use documents and applications in a
+ wide variety of contexts that the author might not have
+ considered.<div class="example">
+
+ <p>As a simple example, consider a Web page written by an author
+ who only considered desktop computer Web browsers. Because HTML
+ conveys <em>meaning</em>, rather than presentation, the same page
+ can also be used by a small browser on a mobile phone, without any
+ change to the page. Instead of headings being in large letters as
+ on the desktop, for example, the browser on the mobile phone might
+ use the same size text for the whole the page, but with the
+ headings in bold.</p>
+
+ <p>But it goes further than just differences in screen size: the
+ same page could equally be used by a blind user using a browser
+ based around speech synthesis, which instead of displaying the page
+ on a screen, reads the page to the user, e.g. using headphones.
+ Instead of large text for the headings, the speech browser might
+ use a different volume or a slower voice.</p>
+
+ <p>That's not all, either. Since the browsers know which parts of
+ the page are the headings, they can create a document outline that
+ the user can use to quickly navigate around the document, using
+ keys for "jump to next heading" or "jump to previous heading". Such
+ features are especially common with speech browsers, where users
+ would otherwise find quickly navigating a page quite difficult.</p>
+
+ <p>Even beyond browsers, software can make use of this information.
+ Search engines can use the headings to more effectively index a
+ page, or to provide quick links to subsections of the page from
+ their results. Tools can use the headings to create a table of
+ contents (that is in fact how this very specification's table of
+ contents is generated).</p>
+
+ <p>This example has focused on headings, but the same principle
+ applies to all of the semantics in HTML.</p>
+
+ </div><p>Authors must not use elements, attributes, or attribute values
+ for purposes other than their appropriate intended semantic purpose,
+ as doing so prevents software from correctly processing the
+ page.<div class="example">
+
<p>For example, the following document is non-conforming, despite
being syntactically correct:</p>
@@ -8306,8 +8344,15 @@
</html></pre>
<p>...because the data placed in the cells is clearly not tabular
- data (and the <code><a href="#the-cite-element">cite</a></code> element mis-used). A corrected
- version of this document might be:</p>
+ data (and the <code><a href="#the-cite-element">cite</a></code> element mis-used). This would make
+ software that relies on these semantics fail: for example, a speech
+ browser that allowed a blind user to navigate tables in the
+ document would report the quote above as a table, confusing the
+ user; similarly, a tool that extracted titles of works from pages
+ would extract "Ernest" as the title of a work, even though it's
+ actually a person's name, not a title.</p>
+
+ <p>A corrected version of this document might be:</p>
<pre><!DOCTYPE HTML>
<html lang="en-GB">
@@ -8323,6 +8368,8 @@
</body>
</html></pre>
+ </div><div class="example">
+
<p>This next document fragment, intended to represent the heading
of a corporate site, is similarly non-conforming because the second
line is not intended to be a heading of a subsection, but merely a
@@ -8344,6 +8391,11 @@
</hgroup>
...</pre>
+ </div><p>Authors must not use elements, attributes, or attribute values
+ that are not permitted by this specification or <a href="#other-applicable-specifications">other
+ applicable specifications</a>, as doing so makes it significantly
+ harder for the language to be extended in the future.<div class="example">
+
<p>In the next example, there is a non-conforming attribute value
("carpet") and a non-conforming attribute ("texture"), which
is not permitted by this specification:</p>
Received on Wednesday, 17 August 2011 00:44:11 UTC