[act] (0) Make <title> optional in HTML e-mails and other such situations.

Fixing http://www.w3.org/Bugs/Public/show_bug.cgi?id=8898

git-svn-id: http://svn.whatwg.org/webapps@4730 340c8d12-0b0e-0410-8428-c7bf67bfef74

Author: Hixie

complete.html

@@ -10633,7 +10633,7 @@ <h4 id=the-head-element-0><span class=secno>4.2.1 </span>The <dfn><code>head</co
    <dt>Contexts in which this element may be used:</dt>
    <dd>As the first element in an <code><a href=#the-html-element-0>html</a></code> element.</dd>
    <dt>Content model:</dt>
-   <dd>If the document is <a href=#an-iframe-srcdoc-document>an <code>iframe</code> <code title=attr-iframe-srcdoc>srcdoc</code> document</a>: Zero or more elements of <a href=#metadata-content>metadata content</a>.</dd>
+   <dd>If the document is <a href=#an-iframe-srcdoc-document>an <code>iframe</code> <code title=attr-iframe-srcdoc>srcdoc</code> document</a> or if title information is available from a higher-level protocol: Zero or more elements of <a href=#metadata-content>metadata content</a>.</dd>
    <dd>Otherwise: One or more elements of <a href=#metadata-content>metadata content</a>, of which exactly one is a <code><a href=#the-title-element-0>title</a></code> element.</dd>
    <dt>Content attributes:</dt>
    <dd><a href=#global-attributes>Global attributes</a></dd>
@@ -10675,6 +10675,12 @@ <h4 id=the-head-element-0><span class=secno>4.2.1 </span>The <dfn><code>head</co
 
   </div>
 
+  <p class=note>The <code><a href=#the-title-element-0>title</a></code> element is a required child
+  in most situations, but when a higher-level protocol provides title
+  information, e.g. in the Subject line of an e-mail when HTML is used
+  as an e-mail authoring format, the <code><a href=#the-title-element-0>title</a></code> element can be
+  omitted.</p>
+
 
 
   <h4 id=the-title-element-0><span class=secno>4.2.2 </span>The <dfn><code>title</code></dfn> element</h4>

index

@@ -10532,7 +10532,7 @@ gave me some of the songs they wrote. I love sharing my music.</p>
    <dt>Contexts in which this element may be used:</dt>
    <dd>As the first element in an <code><a href=#the-html-element-0>html</a></code> element.</dd>
    <dt>Content model:</dt>
-   <dd>If the document is <a href=#an-iframe-srcdoc-document>an <code>iframe</code> <code title=attr-iframe-srcdoc>srcdoc</code> document</a>: Zero or more elements of <a href=#metadata-content>metadata content</a>.</dd>
+   <dd>If the document is <a href=#an-iframe-srcdoc-document>an <code>iframe</code> <code title=attr-iframe-srcdoc>srcdoc</code> document</a> or if title information is available from a higher-level protocol: Zero or more elements of <a href=#metadata-content>metadata content</a>.</dd>
    <dd>Otherwise: One or more elements of <a href=#metadata-content>metadata content</a>, of which exactly one is a <code><a href=#the-title-element-0>title</a></code> element.</dd>
    <dt>Content attributes:</dt>
    <dd><a href=#global-attributes>Global attributes</a></dd>
@@ -10574,6 +10574,12 @@ gave me some of the songs they wrote. I love sharing my music.&lt;/p&gt;
 
   </div>
 
+  <p class=note>The <code><a href=#the-title-element-0>title</a></code> element is a required child
+  in most situations, but when a higher-level protocol provides title
+  information, e.g. in the Subject line of an e-mail when HTML is used
+  as an e-mail authoring format, the <code><a href=#the-title-element-0>title</a></code> element can be
+  omitted.</p>
+
 
 
   <h4 id=the-title-element-0><span class=secno>4.2.2 </span>The <dfn><code>title</code></dfn> element</h4>

source

@@ -10947,7 +10947,7 @@ gave me some of the songs they wrote. I love sharing my music.</p>
    <dt>Contexts in which this element may be used:</dt>
    <dd>As the first element in an <code>html</code> element.</dd>
    <dt>Content model:</dt>
-   <dd>If the document is <span>an <code>iframe</code> <code title="attr-iframe-srcdoc">srcdoc</code> document</span>: Zero or more elements of <span>metadata content</span>.</dd>
+   <dd>If the document is <span>an <code>iframe</code> <code title="attr-iframe-srcdoc">srcdoc</code> document</span> or if title information is available from a higher-level protocol: Zero or more elements of <span>metadata content</span>.</dd>
    <dd>Otherwise: One or more elements of <span>metadata content</span>, of which exactly one is a <code>title</code> element.</dd>
    <dt>Content attributes:</dt>
    <dd><span>Global attributes</span></dd>
@@ -10991,6 +10991,12 @@ gave me some of the songs they wrote. I love sharing my music.&lt;/p>
 
   </div>
 
+  <p class="note">The <code>title</code> element is a required child
+  in most situations, but when a higher-level protocol provides title
+  information, e.g. in the Subject line of an e-mail when HTML is used
+  as an e-mail authoring format, the <code>title</code> element can be
+  omitted.</p>
+
 
 
   <h4>The <dfn><code>title</code></dfn> element</h4>