test/html-webhacc/error-description-source.xml

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:d="http://suika.fam.cx/~wakaba/archive/2007/wdcc-desc/"
    id="error-description">
<head>
<title xml:lang="en">Description of Errors &#x2014; 
Web Document Conformance Checker (BETA)</title>
<link rel="stylesheet" href="cc-style"/>
<link rel="license" href="#license"/>
</head>
<body>
<h1>Description of Errors</h1>

<section id="html5-character-encoding">
<h2>HTML5 Character Encoding Errors</h2>

<d:item name="character encoding" class="format-charset must" level="m">
  <d:message xml:lang="en">Character encoding <code><var>$0</var></code>
  is not allowed for <abbr>HTML</abbr> document.</d:message>
  <d:desc xml:lang="en">
    <p>The character encoding used for the document is not allowed
    for <abbr>HTML</abbr> document.  The document is non‐conforming.</p>
  </d:desc>
</d:item>

<d:item name="character encoding" class="format-charset should"
    level="s">
  <d:message xml:lang="en">Character encoding <code><var>$0</var></code>
  should not be used for <abbr>HTML</abbr> document.</d:message>
  <d:desc xml:lang="en">
    <p>The character encoding used for the document is not recommended
    for <abbr>HTML</abbr> document.  The document is non‐conforming
    unless there is any good reason to use that encoding.</p>
  </d:desc>
</d:item>

<d:item name="character encoding" class="format-charset warning"
    level="w">
  <d:message xml:lang="en">Use of UTF-8 is encouraged.</d:message>
  <d:desc xml:lang="en">
    <p>Use of UTF-8 as the character encoding of the document is encouraged,
    though the use of another character encoding is conforming.</p>
  </d:desc>
</d:item>

<d:item name="character encoding" class="format-charset unsupported"
    level="unsupported">
  <d:message xml:lang="en">Conformance for character encoding requirements
  cannot be checked.</d:message>
  <d:desc xml:lang="en">
    <p>The conformance checker cannot detect whether the input document
    met the requirements on character encoding, since the document
    is not inputed as a serialized byte sequence.  The document is
    not conforming if it is not encoded in an appropriate character
    encoding with appropriate labeling.</p>
  </d:desc>
</d:item>

<d:item name="no character encoding declaration" class="format-charset error"
    level="m">
  <d:message xml:lang="en">There is no character encoding
  declaration.</d:message>
  <d:desc xml:lang="en">
    <p>The document does not contain a character encoding 
    declaration.  Unless the character encoding is explicitly 
    specified in lower‐level protocol, e.g. in <abbr>HTTP</abbr>,
    or is implied by <abbr>BOM</abbr>, there must be a character
    encoding declaration.  The document is non‐conforming.</p>

    <p>The long character encoding declaration syntax
    <code class="html bad example">&lt;meta http-equiv="Content-Type" content="text/html; charset=<var>charset-name</var>"></code>
    is obsolete.  The new syntax is:</p>
    <pre class="html example"><code>&lt;meta charset="<var>charset-name</var>"></code></pre>

    <p>Note that the <code>encoding</code> declaration in <abbr>XML</abbr> 
    declaration has no effect for <abbr>HTML</abbr> document.</p>
  </d:desc>
</d:item>

<d:item name="non ascii superset" class="format-charset error"
    level="m">
  <d:message xml:lang="en">No character encoding metadata is found
  in lower‐level protocol nor is there <abbr>BOM</abbr>, while
  character encoding <code><var>$0</var></code>
  is not a superset of <abbr>ASCII</abbr>.</d:message>
  <d:desc xml:lang="en">
    <p>The document is not labeled with character encoding name
    in lower‐level protocol, e.g. in <abbr>HTTP</abbr>, and
    the document is not begin with <abbr>BOM</abbr>.  In addition,
    the character encoding of the document is not a superset of
    <abbr>ASCII</abbr>.  The document is non‐conforming.</p>

    <p>Unless there is a <abbr>BOM</abbr>, the character encoding
    for the document must be specified in e.g. <abbr>HTTP</abbr>‐level,
    as:</p>
    <pre class="http example"><code>Content-Type: text/html; charset=<var>charset-name</var></code></pre>

    <p>Existence of <abbr>HTML</abbr> character encoding declaration, i.e.
    <code class="html example">&lt;meta charset="<var>charset-name</var>"></code>,
    does not allow to omit <code>charset</code> parameter
    for <abbr>HTML</abbr> document encoded in non‐<abbr>ASCII</abbr>
    compatible encoding.</p>

    <p>Character encodings <code>Shift_JIS</code>, <code>Windows-31J</code>,
    and <code>ISO-2022-JP</code> are <em>not</em> a superset of
    <abbr>ASCII</abbr> for the purpose of <abbr>HTML</abbr> conformance.</p>
  </d:desc>
</d:item>

<d:item name="charset label detected" class="format-charset warning"
    level="w">
  <d:message xml:lang="en">While parsing the document as
  <code><var>$0</var></code>, a character encoding declaration specifying
  character encoding as <code><var>$1</var></code> is found.  The document
  is reparsed.</d:message>
  <d:desc xml:lang="en">
    <p>While parsing a document in a character encoding,
    a character encoding declaration which declares the character
    encoding of the document as another character encoding is found.
    The occurence of this warning itself does not make the document
    non‐conforming.  However, the failure of the first attempt to
    to detect the character encoding might be the result of non‐conformance 
    of the document.</p>

    <p>The document will be reparsed from the beginning.  Some error
    or warning might be reported again.</p>

    <p>These are suggestions to avoid this warning:</p>
    <ul>
    <li>Specify <code>charset</code> parameter in the <code>Content-Type</code>
    field in the <abbr>HTTP</abbr> header, as:
    <pre class="HTTP example"><code>Content-Type: text/html; charset="<var>charset-name</var>"</code></pre></li>
    <li>Put the character encoding declaration
    (<code class="html example">&lt;meta charset="<var>charset-name</var>"></code>)
    just after <code class="html example">&lt;head></code> start tag.</li>
    <li>Use <code>UTF-8</code>.</li>
    </ul>
  </d:desc>
</d:item>
</section>

<section id="html5-tokenize-error">
<h2>HTML5 Parse Errors in Tokenization Stage</h2>

<d:item name="after html"
    class="parse-error">
  <d:message xml:lang="en">Tag <code>&lt;<var>$0</var>&gt;</code>
  is not allowed after the end tag <code>&lt;/html></code>.</d:message>
  <d:desc xml:lang="en">
    <p>The start or end tag of an element appears after the
    <code>html</code> element has been closed.  The document is
    non-conforming.</p>

    <p>Any content of the document other than comments
    must be put into the <code>html</code> element.</p>
  </d:desc>
</d:item>

<d:item name="after body"
    class="parse-error">
  <d:message xml:lang="en">Tag <code>&lt;<var>$0</var>&gt;</code>
  is not allowed after the end tag <code>&lt;/body></code>.</d:message>
  <d:desc xml:lang="en">
    <p>The start or end tag of an element appears after the
    <code>body</code> element has been closed.  The document is
    non-conforming.</p>

    <p>Any content of the document other than <code>head</code>
    contents and comments must be put into the <code>body</code>
    element.</p>
  </d:desc>
</d:item>

<d:item name="bare ero"
    class="tokenize-error">
  <d:message xml:lang="en">The <code>&amp;</code> character must
  introduce a reference.</d:message>
  <d:desc xml:lang="en">
    <p>An <code>&amp;</code> character which
    is not part of any reference appears in the input stream.
    The document is non‐conforming.</p>

    <p><em>Any <code>&amp;</code> character in URI (or IRI)
    must be escaped as <code class="example">&amp;amp;</code>.</em></p>

    <p>The <code>&amp;</code> character must
    be the first character of a reference:
      <dl class="switch">
      <dt>Named entity reference</dt>
          <dd><pre class="html example"><code>&amp;<var>entity-name</var>;</code></pre>
          where <var>entity-name</var> is the name of the
          character entity to be referenced.</dd>
      <dt>Numeric character reference</dt>
          <dd><pre class="html example"><code>&amp;#<var>d</var>;</code></pre>
          where <var>d</var> is the decimal representation of
          the code position of the character to be referenced.</dd>
      <dt>Hexadecimal character reference</dt>
          <dd><pre class="html example"><code>&amp;#x<var>h</var>;</code></pre>
          where <var>h</var> is the hexadecimal representation
          of the code position of the character to be referenced.</dd>
      </dl>
    </p>

    <p>To represent <code>&amp;</code> as a data character, use
    named entity reference:
      <pre class="html example"><code>&amp;amp;</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="bare etago"
    class="tokenize-error">
  <d:message xml:lang="en">A <code>&lt;/</code> string is not followed
  by a tag name.</d:message><!-- </ EOF -->
  <d:desc xml:lang="en">
    <p>There is a <code>&lt;</code> (<code>U+003C</code> 
    <code class="charname">LESS-THAN SIGN</code>) character
    immediately followed by a <code>/</code> (<code>U+005F</code>
    <code>SOLIDUS</code>) character, which is not part
    of any end tag, in the input stream.  The document
    is non-conforming.</p>

    <p>The <code>&lt;/</code> sequence immediately followed
    by an <abbr title="End of file pseudo-character">EOF</abbr> is
    interpreted as a string data of <code>&lt;/</code>.</p>

    <p>The <code>&lt;/</code> sequence as string data must
    be escaped as:
    <pre class="html example"><code>&amp;lt;/</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="bare stago"
    class="tokenize-error">
  <d:message xml:lang="en">A <code>&lt;</code> character is not followed
  by tag name or by a <code>!</code> character.</d:message>
  <d:desc xml:lang="en">
    <p>A <code>&lt;</code> (<code>U+003C</code> 
    <code class="charname">LESS-THAN SIGN</code>) character which is not part
    of any markup appears in the input stream.</p>

    <p>The <code>&lt;</code> character as a data character must
    be escaped as:
    <pre class="html example"><code>&amp;lt;</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="bare nero"
    class="tokenize-error">
  <d:message xml:lang="en">The decimal representation of the code position
  of a character must be specified after <code>&amp;#</code>.</d:message>
  <d:desc xml:lang="en">
    <p>An <code>&amp;</code> (<code>U+0026</code>
    <code class="charname">AMPERSAND</code>) character immediately
    followed by a <code>#</code> (<code>U+0023</code>
    <code>NUMBER SIGN</code>) character which
    is not part of any reference appears in the input stream.
    The document is non-conforming.</p>

    <p>The string <code>&amp;#</code> must be the first two characters
    of a reference:
      <dl class="switch">
      <dt>Numeric character reference</dt>
          <dd><pre class="html example"><code>&amp;#<var>d</var>;</code></pre>
          where <var>d</var> is the decimal representation of
          the code point of the character to be referenced.</dd>
      <dt>Hexadecimal character reference</dt>
          <dd><pre class="html example"><code>&amp;#x<var>h</var>;</code></pre>
          where <var>h</var> is the hexadecimal representation
          of the code point of the character to be referenced.</dd>
      </dl>
    </p>

    <p>To represent <code>&amp;#</code> as data characters, use
    a named entity reference for the <code>&amp;</code> character:
      <pre class="html example"><code>&amp;amp;#</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="bare hcro"
    class="tokenize-error">
  <d:message xml:lang="en">The hexadecimal representation of the code position
  of a character must be specified after <code>&amp;#x</code>.</d:message>
  <d:desc xml:lang="en">
   <p>The string <code>&amp;#x</code> or <code>&amp;#X</code> which
   is not part of any reference appears in the input stream.
    The document is non-conforming.</p>

    <p>The string <code>&amp;#x</code> or <code>&amp;#X</code> must
    be the first three characters of a hexadecimal reference:
      <pre class="html example"><code>&amp;#x<var>h</var>;</code></pre>
    where <var>h</var> is the hexadecimal representation
    of the code point of the character to be referenced.</p>

    <p>To represent <code>&amp;#x</code> as data characters, use
    a named entity reference for the <code>&amp;</code> character:
      <pre class="html example"><code>&amp;amp;#x</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="bogus comment"
    class="tokenize-error">
  <d:message xml:lang="en">String <code>&lt;!</code> is not followed
  by <code>--</code>.</d:message>
  <d:desc xml:lang="en">
    <p>There is a <code>&lt;</code> (<code>U+003C</code> 
    <code class="charname">LESS-THAN SIGN</code>) character
    followed by a <code>!</code> (<code>U+0021</code>
    <code class="charname">EXCLAMATION MARK</code>) character,
    which is not followed by a <code>--</code> or
    <code>!DOCTYPE</code>.  The document is non-conforming.</p>

    <dl class="switch">
    <dt>Comments</dt>
      <dd>In HTML document, comments must be introduced by
      <code class="example">&lt;!--</code> (<code>&lt;!</code>
      <em>immediately</em> followed
      by <em>two</em> <code>-</code>s) and must be terminated by
      <code class="example">--></code>.
      Strings <code>&lt;!</code> not followed
      by <code>--</code> and <code>&lt;!-</code> not followed by
      <code>-</code> are not valid open delimiters for comments.</dd>
    <dt>Marked sections, including <code>CDATA</code> sections</dt>
      <dd>Marked sections are not allowed in HTML document.</dd>
    <dt>Markup declarations</dt>
      <dd>Markup declarations, except for <code>DOCTYPE</code>
      and comment declarations, are not allowed in HTML document.</dd>
    <dt>String <code>&lt;!</code></dt>
      <dd>String <code>&lt;!</code> must be escaped as
      <code class="example">&amp;lt;!</code>.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="bogus end tag"
    class="tokenize-error">
  <d:message xml:lang="en">String <code>&lt;/</code> is not followed
  by tag name.</d:message><!-- </ non-name-start-char-non-EOF -->
  <d:desc xml:lang="en">
    <p>There is a <code>&lt;</code> (<code>U+003C</code> 
    <code class="charname">LESS-THAN SIGN</code>) character
    immediately followed by a <code>/</code> (<code>U+005F</code>
    <code>SOLIDUS</code>) character, which is not part
    of any end tag, in the input stream.  The document
    is non-conforming.</p>

    <p>The <code>&lt;/</code> sequence not followed by a
    tag name is parsed as an opening of bogus comment.</p>

    <p>The <code>&lt;/</code> sequence as string data must
    be escaped as:
    <pre class="html example"><code>&amp;lt;/</code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="dash in comment"
    class="tokenize-error">
  <d:message xml:lang="en">There is a <code>--</code> sequence
  in a comment.</d:message>
  <d:desc xml:lang="en">
    <p>There is a <code>-</code> (<code>U+002D</code>
    <code class="charname">HYPHEN-MINUS</code>) character 
    at the end of the comment or a <code>--</code> sequence
    in the comment.  The document is non-conforming.</p>

    <p>Comments cannot contain a string <code>--</code>, as in XML.
    Unlike SGML, there cannot be more than one comments
    (where <i>comment</i> is an SGML term) in the comment
    declaration.</p>
  </d:desc>
</d:item>

<d:item name="duplicate attribute"
    class="tokenize-error">
  <d:message xml:lang="en">There are two attributes with name
      <code><var>$0</var></code>.</d:message>
  <d:desc xml:lang="en">
    <p>There are more than one attributes with the same
    name in a tag.  The document is non-conforming.</p>

    <p>The <code>motion</code> attribute is not part of the HTML standard.
    Use <code>img</code> element with animation GIF instead.</p>
  </d:desc>
</d:item>

<d:item name="nestc"
    class="tokenize-error">
  <d:message xml:lang="en">Polytheistic slash (<code>/></code>) cannot be
  used for this element.</d:message>
  <d:desc xml:lang="en">
    <p>Polytheistic slash (<code>/></code>) must not be used
    for the element.  The document is non-conforming.</p>

    <p>The pol
1	wakaba	1.1	<!DOCTYPE html>
2			<html xmlns="http://www.w3.org/1999/xhtml"
3			xmlns:d="http://suika.fam.cx/~wakaba/archive/2007/wdcc-desc/"
4			id="error-description">
5			<head>
6			<title xml:lang="en">Description of Errors —
7			Web Document Conformance Checker (BETA)</title>
8			<link rel="stylesheet" href="cc-style"/>
9			<link rel="license" href="#license"/>
10			</head>
11			<body>
12			<h1>Description of Errors</h1>
13
14	wakaba	1.16	<section id="html5-character-encoding">
15			<h2>HTML5 Character Encoding Errors</h2>
16
17			<d:item name="character encoding" class="format-charset must" level="m">
18			<d:message xml:lang="en">Character encoding <code><var>$0</var></code>
19			is not allowed for <abbr>HTML</abbr> document.</d:message>
20			<d:desc xml:lang="en">
21			<p>The character encoding used for the document is not allowed
22			for <abbr>HTML</abbr> document. The document is non‐conforming.</p>
23			</d:desc>
24			</d:item>
25
26			<d:item name="character encoding" class="format-charset should"
27			level="s">
28			<d:message xml:lang="en">Character encoding <code><var>$0</var></code>
29			should not be used for <abbr>HTML</abbr> document.</d:message>
30			<d:desc xml:lang="en">
31			<p>The character encoding used for the document is not recommended
32			for <abbr>HTML</abbr> document. The document is non‐conforming
33			unless there is any good reason to use that encoding.</p>
34			</d:desc>
35			</d:item>
36
37			<d:item name="character encoding" class="format-charset warning"
38			level="w">
39			<d:message xml:lang="en">Use of UTF-8 is encouraged.</d:message>
40			<d:desc xml:lang="en">
41			<p>Use of UTF-8 as the character encoding of the document is encouraged,
42			though the use of another character encoding is conforming.</p>
43			</d:desc>
44			</d:item>
45
46	wakaba	1.17	<d:item name="character encoding" class="format-charset unsupported"
47			level="unsupported">
48			<d:message xml:lang="en">Conformance for character encoding requirements
49			cannot be checked.</d:message>
50			<d:desc xml:lang="en">
51			<p>The conformance checker cannot detect whether the input document
52			met the requirements on character encoding, since the document
53			is not inputed as a serialized byte sequence. The document is
54			not conforming if it is not encoded in an appropriate character
55			encoding with appropriate labeling.</p>
56			</d:desc>
57			</d:item>
58
59	wakaba	1.16	<d:item name="no character encoding declaration" class="format-charset error"
60			level="m">
61			<d:message xml:lang="en">There is no character encoding
62			declaration.</d:message>
63			<d:desc xml:lang="en">
64			<p>The document does not contain a character encoding
65			declaration. Unless the character encoding is explicitly
66	wakaba	1.17	specified in lower‐level protocol, e.g. in <abbr>HTTP</abbr>,
67	wakaba	1.16	or is implied by <abbr>BOM</abbr>, there must be a character
68			encoding declaration. The document is non‐conforming.</p>
69
70			<p>The long character encoding declaration syntax
71			<code class="html bad example"><meta http-equiv="Content-Type" content="text/html; charset=<var>charset-name</var>"></code>
72			is obsolete. The new syntax is:</p>
73			<pre class="html example"><code><meta charset="<var>charset-name</var>"></code></pre>
74
75			<p>Note that the <code>encoding</code> declaration in <abbr>XML</abbr>
76			declaration has no effect for <abbr>HTML</abbr> document.</p>
77			</d:desc>
78			</d:item>
79
80			<d:item name="non ascii superset" class="format-charset error"
81			level="m">
82			<d:message xml:lang="en">No character encoding metadata is found
83	wakaba	1.17	in lower‐level protocol nor is there <abbr>BOM</abbr>, while
84	wakaba	1.16	character encoding <code><var>$0</var></code>
85			is not a superset of <abbr>ASCII</abbr>.</d:message>
86			<d:desc xml:lang="en">
87			<p>The document is not labeled with character encoding name
88	wakaba	1.17	in lower‐level protocol, e.g. in <abbr>HTTP</abbr>, and
89	wakaba	1.16	the document is not begin with <abbr>BOM</abbr>. In addition,
90			the character encoding of the document is not a superset of
91			<abbr>ASCII</abbr>. The document is non‐conforming.</p>
92
93			<p>Unless there is a <abbr>BOM</abbr>, the character encoding
94			for the document must be specified in e.g. <abbr>HTTP</abbr>‐level,
95			as:</p>
96			<pre class="http example"><code>Content-Type: text/html; charset=<var>charset-name</var></code></pre>
97
98			<p>Existence of <abbr>HTML</abbr> character encoding declaration, i.e.
99			<code class="html example"><meta charset="<var>charset-name</var>"></code>,
100			does not allow to omit <code>charset</code> parameter
101			for <abbr>HTML</abbr> document encoded in non‐<abbr>ASCII</abbr>
102			compatible encoding.</p>
103
104			<p>Character encodings <code>Shift_JIS</code>, <code>Windows-31J</code>,
105			and <code>ISO-2022-JP</code> are <em>not</em> a superset of
106			<abbr>ASCII</abbr> for the purpose of <abbr>HTML</abbr> conformance.</p>
107			</d:desc>
108			</d:item>
109
110			<d:item name="charset label detected" class="format-charset warning"
111			level="w">
112			<d:message xml:lang="en">While parsing the document as
113			<code><var>$0</var></code>, a character encoding declaration specifying
114			character encoding as <code><var>$1</var></code> is found. The document
115			is reparsed.</d:message>
116			<d:desc xml:lang="en">
117			<p>While parsing a document in a character encoding,
118			a character encoding declaration which declares the character
119			encoding of the document as another character encoding is found.
120			The occurence of this warning itself does not make the document
121			non‐conforming. However, the failure of the first attempt to
122			to detect the character encoding might be the result of non‐conformance
123			of the document.</p>
124
125			<p>The document will be reparsed from the beginning. Some error
126			or warning might be reported again.</p>
127
128			<p>These are suggestions to avoid this warning:</p>
129			<ul>
130			<li>Specify <code>charset</code> parameter in the <code>Content-Type</code>
131			field in the <abbr>HTTP</abbr> header, as:
132			<pre class="HTTP example"><code>Content-Type: text/html; charset="<var>charset-name</var>"</code></pre></li>
133			<li>Put the character encoding declaration
134			(<code class="html example"><meta charset="<var>charset-name</var>"></code>)
135			just after <code class="html example"><head></code> start tag.</li>
136			<li>Use <code>UTF-8</code>.</li>
137			</ul>
138			</d:desc>
139			</d:item>
140			</section>
141
142	wakaba	1.2	<section id="html5-tokenize-error">
143			<h2>HTML5 Parse Errors in Tokenization Stage</h2>
144	wakaba	1.1
145	wakaba	1.3	<d:item name="after html"
146			class="parse-error">
147			<d:message xml:lang="en">Tag <code><<var>$0</var>></code>
148			is not allowed after the end tag <code></html></code>.</d:message>
149			<d:desc xml:lang="en">
150			<p>The start or end tag of an element appears after the
151			<code>html</code> element has been closed. The document is
152			non-conforming.</p>
153
154			<p>Any content of the document other than comments
155			must be put into the <code>html</code> element.</p>
156			</d:desc>
157			</d:item>
158
159	wakaba	1.7	<d:item name="after body"
160			class="parse-error">
161			<d:message xml:lang="en">Tag <code><<var>$0</var>></code>
162			is not allowed after the end tag <code></body></code>.</d:message>
163			<d:desc xml:lang="en">
164			<p>The start or end tag of an element appears after the
165			<code>body</code> element has been closed. The document is
166			non-conforming.</p>
167
168			<p>Any content of the document other than <code>head</code>
169			contents and comments must be put into the <code>body</code>
170			element.</p>
171			</d:desc>
172			</d:item>
173
174	wakaba	1.3	<d:item name="bare ero"
175			class="tokenize-error">
176			<d:message xml:lang="en">The <code>&</code> character must
177			introduce a reference.</d:message>
178			<d:desc xml:lang="en">
179	wakaba	1.15	<p>An <code>&</code> character which
180	wakaba	1.3	is not part of any reference appears in the input stream.
181	wakaba	1.15	The document is non‐conforming.</p>
182	wakaba	1.3
183	wakaba	1.15	<p><em>Any <code>&</code> character in URI (or IRI)
184			must be escaped as <code class="example">&amp;</code>.</em></p>
185	wakaba	1.9
186	wakaba	1.3	<p>The <code>&</code> character must
187			be the first character of a reference:
188	wakaba	1.15	<dl class="switch">
189	wakaba	1.3	<dt>Named entity reference</dt>
190			<dd><pre class="html example"><code>&<var>entity-name</var>;</code></pre>
191			where <var>entity-name</var> is the name of the
192			character entity to be referenced.</dd>
193			<dt>Numeric character reference</dt>
194			<dd><pre class="html example"><code>&#<var>d</var>;</code></pre>
195			where <var>d</var> is the decimal representation of
196			the code position of the character to be referenced.</dd>
197			<dt>Hexadecimal character reference</dt>
198			<dd><pre class="html example"><code>&#x<var>h</var>;</code></pre>
199			where <var>h</var> is the hexadecimal representation
200			of the code position of the character to be referenced.</dd>
201			</dl>
202			</p>
203
204			<p>To represent <code>&</code> as a data character, use
205			named entity reference:
206			<pre class="html example"><code>&amp;</code></pre>
207			</p>
208			</d:desc>
209			</d:item>
210
211	wakaba	1.7	<d:item name="bare etago"
212			class="tokenize-error">
213			<d:message xml:lang="en">A <code></</code> string is not followed
214			by a tag name.</d:message><!-- </ EOF -->
215			<d:desc xml:lang="en">
216			<p>There is a <code><</code> (<code>U+003C</code>
217			<code class="charname">LESS-THAN SIGN</code>) character
218			immediately followed by a <code>/</code> (<code>U+005F</code>
219			<code>SOLIDUS</code>) character, which is not part
220			of any end tag, in the input stream. The document
221			is non-conforming.</p>
222
223			<p>The <code></</code> sequence immediately followed
224			by an <abbr title="End of file pseudo-character">EOF</abbr> is
225			interpreted as a string data of <code></</code>.</p>
226
227			<p>The <code></</code> sequence as string data must
228			be escaped as:
229			<pre class="html example"><code>&lt;/</code></pre>
230			</p>
231			</d:desc>
232			</d:item>
233
234	wakaba	1.4	<d:item name="bare stago"
235			class="tokenize-error">
236			<d:message xml:lang="en">A <code><</code> character is not followed
237			by tag name or by a <code>!</code> character.</d:message>
238			<d:desc xml:lang="en">
239	wakaba	1.6	<p>A <code><</code> (<code>U+003C</code>
240			<code class="charname">LESS-THAN SIGN</code>) character which is not part
241			of any markup appears in the input stream.</p>
242	wakaba	1.4
243			<p>The <code><</code> character as a data character must
244			be escaped as:
245	wakaba	1.6	<pre class="html example"><code>&lt;</code></pre>
246	wakaba	1.4	</p>
247			</d:desc>
248			</d:item>
249
250	wakaba	1.3	<d:item name="bare nero"
251			class="tokenize-error">
252			<d:message xml:lang="en">The decimal representation of the code position
253			of a character must be specified after <code>&#</code>.</d:message>
254			<d:desc xml:lang="en">
255			<p>An <code>&</code> (<code>U+0026</code>
256			<code class="charname">AMPERSAND</code>) character immediately
257			followed by a <code>#</code> (<code>U+0023</code>
258			<code>NUMBER SIGN</code>) character which
259			is not part of any reference appears in the input stream.
260			The document is non-conforming.</p>
261
262			<p>The string <code>&#</code> must be the first two characters
263			of a reference:
264	wakaba	1.15	<dl class="switch">
265	wakaba	1.3	<dt>Numeric character reference</dt>
266			<dd><pre class="html example"><code>&#<var>d</var>;</code></pre>
267			where <var>d</var> is the decimal representation of
268			the code point of the character to be referenced.</dd>
269			<dt>Hexadecimal character reference</dt>
270			<dd><pre class="html example"><code>&#x<var>h</var>;</code></pre>
271			where <var>h</var> is the hexadecimal representation
272			of the code point of the character to be referenced.</dd>
273			</dl>
274			</p>
275
276			<p>To represent <code>&#</code> as data characters, use
277	wakaba	1.6	a named entity reference for the <code>&</code> character:
278	wakaba	1.3	<pre class="html example"><code>&amp;#</code></pre>
279			</p>
280			</d:desc>
281			</d:item>
282
283			<d:item name="bare hcro"
284			class="tokenize-error">
285			<d:message xml:lang="en">The hexadecimal representation of the code position
286			of a character must be specified after <code>&#x</code>.</d:message>
287			<d:desc xml:lang="en">
288			<p>The string <code>&#x</code> or <code>&#X</code> which
289			is not part of any reference appears in the input stream.
290			The document is non-conforming.</p>
291
292			<p>The string <code>&#x</code> or <code>&#X</code> must
293			be the first three characters of a hexadecimal reference:
294			<pre class="html example"><code>&#x<var>h</var>;</code></pre>
295			where <var>h</var> is the hexadecimal representation
296			of the code point of the character to be referenced.</p>
297
298			<p>To represent <code>&#x</code> as data characters, use
299	wakaba	1.6	a named entity reference for the <code>&</code> character:
300	wakaba	1.3	<pre class="html example"><code>&amp;#x</code></pre>
301			</p>
302			</d:desc>
303			</d:item>
304
305	wakaba	1.9	<d:item name="bogus comment"
306			class="tokenize-error">
307			<d:message xml:lang="en">String <code><!</code> is not followed
308			by <code>--</code>.</d:message>
309			<d:desc xml:lang="en">
310			<p>There is a <code><</code> (<code>U+003C</code>
311			<code class="charname">LESS-THAN SIGN</code>) character
312			followed by a <code>!</code> (<code>U+0021</code>
313			<code class="charname">EXCLAMATION MARK</code>) character,
314			which is not followed by a <code>--</code> or
315			<code>!DOCTYPE</code>. The document is non-conforming.</p>
316
317			<dl class="switch">
318			<dt>Comments</dt>
319	wakaba	1.15	<dd>In HTML document, comments must be introduced by
320			<code class="example"><!--</code> (<code><!</code>
321			<em>immediately</em> followed
322	wakaba	1.9	by <em>two</em> <code>-</code>s) and must be terminated by
323	wakaba	1.15	<code class="example">--></code>.
324			Strings <code><!</code> not followed
325	wakaba	1.9	by <code>--</code> and <code><!-</code> not followed by
326			<code>-</code> are not valid open delimiters for comments.</dd>
327			<dt>Marked sections, including <code>CDATA</code> sections</dt>
328	wakaba	1.15	<dd>Marked sections are not allowed in HTML document.</dd>
329	wakaba	1.9	<dt>Markup declarations</dt>
330	wakaba	1.15	<dd>Markup declarations, except for <code>DOCTYPE</code>
331			and comment declarations, are not allowed in HTML document.</dd>
332	wakaba	1.9	<dt>String <code><!</code></dt>
333			<dd>String <code><!</code> must be escaped as
334	wakaba	1.15	<code class="example">&lt;!</code>.</dd>
335	wakaba	1.9	</dl>
336			</d:desc>
337			</d:item>
338
339	wakaba	1.7	<d:item name="bogus end tag"
340			class="tokenize-error">
341	wakaba	1.9	<d:message xml:lang="en">String <code></</code> is not followed
342			by tag name.</d:message><!-- </ non-name-start-char-non-EOF -->
343	wakaba	1.7	<d:desc xml:lang="en">
344			<p>There is a <code><</code> (<code>U+003C</code>
345			<code class="charname">LESS-THAN SIGN</code>) character
346			immediately followed by a <code>/</code> (<code>U+005F</code>
347			<code>SOLIDUS</code>) character, which is not part
348			of any end tag, in the input stream. The document
349			is non-conforming.</p>
350
351			<p>The <code></</code> sequence not followed by a
352			tag name is parsed as an opening of bogus comment.</p>
353
354			<p>The <code></</code> sequence as string data must
355			be escaped as:
356			<pre class="html example"><code>&lt;/</code></pre>
357			</p>
358			</d:desc>
359			</d:item>
360
361	wakaba	1.4	<d:item name="dash in comment"
362			class="tokenize-error">
363			<d:message xml:lang="en">There is a <code>--</code> sequence
364			in a comment.</d:message>
365			<d:desc xml:lang="en">
366			<p>There is a <code>-</code> (<code>U+002D</code>
367			<code class="charname">HYPHEN-MINUS</code>) character
368			at the end of the comment or a <code>--</code> sequence
369			in the comment. The document is non-conforming.</p>
370
371			<p>Comments cannot contain a string <code>--</code>, as in XML.
372			Unlike SGML, there cannot be more than one comments
373			(where <i>comment</i> is an SGML term) in the comment
374			declaration.</p>
375			</d:desc>
376			</d:item>
377
378	wakaba	1.1	<d:item name="duplicate attribute"
379			class="tokenize-error">
380	wakaba	1.6	<d:message xml:lang="en">There are two attributes with name
381			<code><var>$0</var></code>.</d:message>
382	wakaba	1.1	<d:desc xml:lang="en">
383	wakaba	1.3	<p>There are more than one attributes with the same
384			name in a tag. The document is non-conforming.</p>
385	wakaba	1.1
386			<p>The <code>motion</code> attribute is not part of the HTML standard.
387			Use <code>img</code> element with animation GIF instead.</p>
388			</d:desc>
389			</d:item>
390
391			<d:item name="nestc"
392			class="tokenize-error">
393	wakaba	1.10	<d:message xml:lang="en">Polytheistic slash (<code>/></code>) cannot be
394	wakaba	1.1	used for this element.</d:message>
395			<d:desc xml:lang="en">
396	wakaba	1.10	<p>Polytheistic slash (<code>/></code>) must not be used
397	wakaba	1.3	for the element. The document is non-conforming.</p>
398
399	wakaba	1.10	<p>The pol