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>
<base href="cc/"/>
<title xml:lang="en">Description of Errors &#x2014; WebHACC (β)</title>
<title xml:lang="ja">誤りの説明 &#x2014; WebHACC (β)</title>
<link rel="stylesheet" href="../cc-style"/>
<link rel="license" href="#license"/>
</head>
<body>
<header>
<h1><a href="../cc-about"><abbr title="Web Hypertext Application Conformance Checker (β)"><img src="../icons/title" alt="WebHACC"/></abbr></a></h1>
<h2>Description of Errors</h2>
</header>

<d:cat name="WebHACC:Title">
  <d:text xml:lang="en">WebHACC (β)</d:text>
</d:cat>

<d:cat name="WebHACC:Heading">
  <d:text xml:lang="en">
    <a href="../error-description#WebHACC:Heading" rel="help"><abbr title="Web Hypertext Application Conformance Checker (β)"><img src="../icons/title" alt="WebHACC"/></abbr></a>
  </d:text>
  <d:text xml:lang="ja">
    <a href="../error-description#WebHACC:Heading" rel="help"><abbr title="Web ハイパーテキスト応用適合性検査器 (β)"><img src="../icons/title" alt="WebHACC"/></abbr></a>
  </d:text>
  <d:desc xml:lang="en">
    <p><a href="./#input"><abbr title="Web Hypertext Application Conformance Checker">WebHACC</abbr></a>
    is a <em>conformance checker</em> (or validator) for Web documents,
    supporting <a href="../standards">latest Web standards</a> including
    <a href="http://whatwg.org/html5"><abbr title="Hypertext Markup Language">HTML</abbr>5</a>,
    <a href="urn:ietf:rfc:4287">Atom 1.0</a>,
    <a href="http://www.w3.org/Style/CSS/current-work"><abbr title="Cascading Style Sheets">CSS</abbr>3</a>.</p>

    <p><strong><a href="./#input">Check your document</a></strong>, or
    <a href="../cc-about">learn more about
    <abbr title="Web Hypertext Application Conformance Checker">WebHACC</abbr></a>.</p>
  </d:desc>
  <d:desc xml:lang="ja">
    <p><a href="./#input"><abbr title="Web ハイパーテキスト応用適合性検査器">WebHACC</abbr></a>
    は、 Web 文書のための<em>適合性検査器</em> (妥当性検証器) です。
    <a href="http://whatwg.org/html5"><abbr title="Hypertext Markup Language">HTML</abbr>5</a>、
    <a href="urn:ietf:rfc:4287">Atom 1.0</a>、
    <a href="http://www.w3.org/Style/CSS/current-work"><abbr title="Cascading Style Sheets">CSS</abbr>3</a>
    などの<a href="../standards">最新の Web 標準</a>に対応しています。</p>

    <p><strong><a href="./#input">文書を検査する</a></strong></p>

    <p><a href="../cc-about"><abbr title="Web ハイパーテキスト応用適合性検査器">WebHACC</abbr>
    の詳細</a></p>
  </d:desc>
</d:cat>

<section id="character-encoding-layer">
<h2>Character Encoding Layer Errors</h2>

<d:item name="fallback-char-error"
    modules="Charset::DecodeHandle">
  <d:message xml:lang="en">Octet sequence <code><var>{octets}</var></code>
  is not an allowed representation of the character
  <code><var>{char}</var></code> &#x2014; character reference
  <code><var>{char:hexref}</var></code> should be used instead.</d:message>
  <!-- HTML5 parse error -->
</d:item>

<d:item name="fallback-unassigned-error"
    modules="Charset::DecodeHandle">
  <d:message xml:lang="en">No character is assigned to octet sequence
  <code><var>{octets}</var></code>.</d:message>
  <!-- HTML5 parse error -->
</d:item>

<d:item name="illegal-octets-error"
    modules="Charset::DecodeHandle">
  <d:message xml:lang="en">Octet sequence <code><var>{octets}</var></code>
  is illegal.</d:message>
</d:item>

<d:item name="invalid-state-error"
    modules="Charset::DecodeHandle::ISO2022JP">
  <!-- TODO: more user-friendly error message is desired... -->
  <d:message xml:lang="en">The input stream is broken.</d:message>
  <d:desc xml:lang="en">
    <p>The input stream is encoded in <code>ISO-2022-JP</code>
    or its variant but is partially broken.</p>

    <p>Note that an <code>ISO-2022-JP</code> stream must end in the ASCII
    state.</p>
  </d:desc>
</d:item>

<d:item name="unassigned-code-point-error"
    modules="Charset::DecodeHandle">
  <d:message xml:lang="en">No character is assigned to octet sequence
  <code><var>{octets}</var></code>.</d:message>
</d:item>
</section>

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

<d:item name="disallowed character encoding"
    modules="ContentChecker">
  <d:message xml:lang="en">Character encoding <code><var>{text}</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="bad character encoding"
    modules="ContentChecker">
  <d:message xml:lang="en">Character encoding <code><var>{text}</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="non-utf-8 character encoding"
    modules="ContentChecker">
  <d:message xml:lang="en">Use of UTF-8 is encouraged (this document
  is encoded in <code><var>{text}</var></code>).</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 still conforming.</p>
  </d:desc>
</d:item>

<d:item name="character encoding unchecked"
    modules="ContentChecker">
  <d:message xml:lang="en">Conformance for character encoding requirements
  cannot be checked, since the input is not a byte stream.</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"
    modules="ContentChecker">
  <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"
    modules="ContentChecker">
  <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>{text}</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="sniffing:chardet"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character encoding of this document is sniffed
  as <code><var>{text}</var></code> (Sniffed because no explicit specification
  for the character encoding of this document is found in the transfer
  procotol headers).</d:message>
</d:item>

<d:item name="sniffing:default"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character encoding of this document is defaulted
  to <code><var>{text}</var></code> because no explicit specification
  for the character encoding of this document is found in the transfer
  procotol headers.</d:message>
</d:item>

<d:item name="chardecode:fallback"
    modules="HTML::Parser">
  <d:message xml:lang="en">Results might be <em>wrong</em>, since the
  conformance checker cannot find an appropriate decoder for the character
  encoding used for the document.</d:message>
  <d:desc xml:lang="en">
    <p>The conformance checker cannot find an appropriate decoder for
    the character encoding used to encode characters in the document.</p>

    <p>This error is raised if:</p>
    <ul>
    <li>the conformance checker cannot find any decoder for the character
    encoding in use, but it knows that the encoding is similar to another
    character encoding, such that it uses the decoder for that character
    encoding, and therefore some octets might be interpreted incorrectly,
    or,</li>
    <li>the conformance checker find a decoder for the character encoding
    in use, but it does not know whether the decoder is conforming to the
    relevant specification or not, and therefore some octets might be
    interpreted incorrectly.</li>
    </ul>

    <p>In either case, the result shown by the conformance checker might
    contain wrong errors caused by errorneous decoder or might not contain 
    errors that should be raised if an appropriate decoder is used.</p>

    <!-- TODO: add advise that either install relevant modules or 
         join the developmenet of the modules... -->
  </d:desc>
</d:item>

<d:item name="chardecode:no error"
    modules="HTML::Parser">
  <d:message xml:lang="en">Conformance error checking for the character
  encoding <code><var>{text}</var></code> is not supported.</d:message>
</d:item>

<d:item name="charset label:matching"
    modules="HTML::Parser">
  <d:message xml:lang="en">Sniffed character encoding 
  <code><var>{text}</var></code> is same as the character encoding specified
  in the character encoding declaration.  This is <em>not</em> an
  error.</d:message>
</d:item>

<d:item name="charset label detected"
    modules="HTML::Parser">
  <d:message xml:lang="en">While parsing the document as
  <code><var>{text}</var></code>, a character encoding declaration specifying
  a different character encoding 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 a 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="character-set-layer">
<h2>Coded Character Set Layer Errors</h2>

<d:item name="NULL"
    modules="HTML::Parser">
  <!-- HTML5 Parse Error -->
  <d:message xml:lang="en">The <code class="charname">NULL</code> character
  is not allowed.</d:message>
</d:item>

<d:item name="control char"
    modules="HTML::Parser">
  <!-- HTML5 Parse Error -->
  <d:message xml:lang="en">Code point <code><var>{text}</var></code> is
  not allowed.</d:message>
</d:item>

<d:item name="nonchar"
    modules="Charset::UnicodeChecker">
  <d:message xml:lang="en">Noncharacter <code><var>{text}</var></code>
  is found in the input stream.</d:message>
  <d:desc xml:lang="en">
    <p>Noncharacter code points are used in the input stream.</p>

    <p>Noncharacter code points are reserved for internal processings.
    Their use for information interchanges are forbidden.</p>

    <p>In addition, they are not allowed in HTML document.</p>
    <!-- "permanently undefined Unicode characters" in HTML5. -->
  </d:desc>
</d:item>

<d:item name="unicode deprecated"
    modules="Charset::UnicodeChecker">
  <d:message xml:lang="en">Use of character <code><var>{text}</var></code>
  is deprecated.</d:message>
</d:item>

<d:item name="unicode discouraged"
    modules="Charset::UnicodeChecker">
  <d:message xml:lang="en">Use of character <code><var>{text}</var></code>
  is discouraged.</d:message>
</d:item>

<d:item name="unicode not preferred"
    modules="Charset::UnicodeChecker">
  <d:message xml:lang="en">Code point <code><var>{text}</var></code>
  is not the preferred representation of that character.</d:message>
</d:item>

<d:item name="unicode should"
    modules="Charset::UnicodeChecker">
  <d:message xml:lang="en">Character <code><var>{text}</var></code>
  should not be used in many cases.</d:message>
</d:item>

</section>

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

<d:item name="bad attribute name"
    modules="HTML::Parser">
  <d:message xml:lang="en">Attribute name cannot contain characters
  <code>"</code>, <code>'</code>, and <code>=</code>.</d:message>
</d:item>

<d:item name="bad attribute value"
    modules="HTML::Parser">
  <d:message xml:lang="en">Attribute value must be quoted by <code>"</code>
  or <code>'</code> if it contains a <code>"</code>, <code>'</code>, or
  <code>=</code> character.</d:message>
  <d:desc xml:lang="en">
    <p>In an unquoted attribute value, a character <code>"</code>
    (<code>U+0022</code> <code class="charname">QUOTATION MARK</code>),
    <code>'</code> (<code>U+0026</code> 
    <code class="charname">APOSTROPHE</code>), or <code>=</code>
    (<code>U+003D</code> <code class="charname">EQUAL SIGN</code>)
    is contained.  These characters are not allowed in unquoted attribute
    values, since they are used to quote attribute values or to separate
    attribute name and value.</p>

    <p>This error is also raised if one try to use empty attribute
    value like <code class="html bad example">&lt;foo bar= baz=></code>;
    in this example, <code class="html bad example">baz=</code> is
    treated as an invalid attribute value for the attribute
    <code class="html bad example">bar</code>, not as another attribute.</p>
  </d:desc>
</d:item>

<d:item name="bare ero"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>&amp;</code> character must
  be escaped as <code class="html example">&amp;amp;</code>.</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"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <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="C1 character reference"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character reference to
  <code><var>{text}</var></code> is not allowed.</d:message>
</d:item>

<d:item name="CR character reference"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character reference to
  <code>U+000D</code> (<code class="charname">CARRIAGE RETURN</code>)
  is not allowed.</d:message>
</d:item>

<d:item name="dash in comment"
    modules="HTML::Parser">
  <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"
    modules="HTML::Parser">
  <d:message xml:lang="en">There are two attributes with name
      <code><var>{text}</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="empty start tag"
    modules="HTML::Parser">
  <d:message xml:lang="en">Empty start tag (<code>&lt;></code>) is not
  allowed.</d:message>
</d:item>

<d:item name="empty end tag"
    modules="HTML::Parser">
  <d:message xml:lang="en">Empty end tag (<code>&lt;/></code>) is not
  allowed.</d:message>
</d:item>

<d:item name="end tag attribute"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag cannot have attributes.</d:message>
  <d:message xml:lang="ja">終了タグに属性が指定されています。</d:message>
</d:item>

<d:item name="empty unquoted attribute value"
    modules="HTML::Parser">
  <d:message xml:lang="en">Attribute value is not specified.</d:message>
  <d:message xml:lang="ja">属性値が指定されていません。</d:message>
  <d:desc xml:lang="en">
    <p>The attribute value is not specified after the <code>=</code>
    (<code>U+003C</code> <code class="charname">EQUAL SIGN</code>)
    character.</p>

    <p>When an attribute value is empty, the <code>=</code> character after
    the attribute name must be specified as:</p>

    <p><code class="html example">&lt;foo bar></code></p>

    <p>Instead, quotation marks can be used to explicitly represent that
    the attribute value is empty, as:</p>

    <p><code class="html example">&lt;foo bar=""></code></p>

    <p>... or like:</p>

    <p><code class="html example">&lt;foo bar=''></code></p>
  </d:desc>
</d:item>

<d:item name="invalid character reference"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character reference to
  <code><var>{text}</var></code> is not allowed.</d:message>
</d:item>

<d:item name="nestc"
    modules="HTML::Parser">
  <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 polytheistic slash can only be
    used for <code>base</code>, <code>link</code>, <code>meta</code>,
    <code>hr</code>, <code>br</code>, <code>img</code>, 
    <code>embed</code>, <code>param</code>, <code>area</code>,
    <code>col</code>, and <code>input</code> elements.</p>

    <dl class="switch">
    <dt><code>&lt;script/></code></dt>
        <dd><p>The polytheistic slash cannot be used for <code>script</code>
        element.  Even for an empty <code>script</code> element,
        there must be an explicit end tag
        <code class="html example">&lt;/script></code>.</p>

        <p><strong>NOTE</strong>: Though some user agents interpret
        polytheistic slash for <code>script</code> element as the 
        closing of the element, such usage is not allowed under
        the current standard.</p></dd>
    <dt><code>&lt;basefont/></code>, <code>&lt;bgsound/></code>,
    <code>&lt;frame/></code>, <code>&lt;keygen/></code>,
    <code>&lt;spacer/></code>, <code>&lt;wbr/></code></dt>
        <dd>These elements are themselves non-conforming.</dd>
    <!-- isindex, image -->
    <dt><code>&lt;command/></code>, <code>&lt;event-source/></code>,
    <code>&lt;nest/></code>, or <code>&lt;source/></code></dt>
        <dd>Future revision of HTML5 parsing algorithm is expected
        to allow polytheistic slash for these elements.</dd>
    <dt><code>&lt;a/></code>, <code>&lt;p/></code></dt>
        <dd>These elements are not always empty and therefore
        polytheistic slash is not allowed.  Use explicit end tag
        to represent empty element as:
          <pre class="example html"><code>&lt;p>&lt;/p></code></pre>
        </dd>
    </dl>

    <p>Note that, unlike in XML, the polytheistic slash has
    no effect in HTML.</p>
  </d:desc>
</d:item>

<d:item name="no DOCTYPE name"
    modules="HTML::Parser">
  <d:message xml:lang="en">After the string <code>&lt;!DOCTYPE </code>, the
  document type name must be specified.</d:message>
</d:item>

<d:item name="no PUBLIC literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">After the keyword <code>PUBLIC</code>, no
  oublic identifier is specified.</d:message>
</d:item>

<d:item name="no refc"
    modules="HTML::Parser">
  <d:message xml:lang="en">Character reference must be closed by a
  <code>;</code> character.</d:message>
</d:item>

<d:item name="no space before DOCTYPE name"
    modules="HTML::Parser">
  <d:message xml:lang="en">After the string <code>&lt;!DOCTYPE</code>, there
  must be at least a white space character before the document type
  name.</d:message>
</d:item>

<d:item name="no space between attributes"
    modules="HTML::Parser">
  <d:message xml:lang="en">Attributes must be separeted by at least a
  white space character.</d:message>
</d:item>

<d:item name="no SYSTEM literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">After the keyword <code>SYSTEM</code>, no
  system identifier is specified.</d:message>
</d:item>

<d:item name="pio"
    modules="HTML::Parser">
  <d:message xml:lang="en">Processing instruction 
  (<code>&lt;?<var>...</var>></code>) is not allowed in HTML
  document.</d:message>
  <d:desc xml:lang="en">
    <p>Processing instructions (<code>&lt;?<var>...</var>?></code>),
    including XML declaration (<code>&lt;?xml <var>...</var>?></code>)
    and XML style sheet <abbr title="processing instruction">PI</abbr>
    (<code>&lt;?xml-stylesheet <var>...</var>?></code>), are not allowed 
    in the HTML syntax.  The document is non-conforming.</p>

    <dl class="switch">
    <dt><code>&lt;?xbl?></code> (<abbr>XBL</abbr> Association)</dt>
      <dd>An <abbr>XBL</abbr> binding cannot be associated by 
      <abbr title="processing instruction">PI</abbr> in <abbr>HTML</abbr>
      document.  Use <code>binding</code> property in <abbr>CSS</abbr>
      style sheet as:
        <pre class="html example"><code>&lt;style>
p {
  binding: url(binding.xbl);
}
&lt;/style></code></pre>
      </dd>
    <dt><code>&lt;?xml?&gt;</code> (XML declaration)</dt>
        <dd>XML declaration is unnecessary for HTML documents.</dd>
    <dt><code>&lt;?xml-stylesheet?></code> (XML style sheet
    <abbr title="processing instruction">PI</abbr>)</dt>
        <dd>Use HTML <code>link</code> element with <code>rel</code>
        attribute set to <code>stylesheet</code> (or,
        <code>alternate stylesheet</code> for an alternate style 
        sheet).
          <pre class="example html"><code>&lt;link rel=stylesheet href="path/to/stylesheet.css"></code></pre>
        </dd>
    <dt><code>&lt;?php?&gt;</code> or 
    <code>&lt;? <var>... <abbr>PHP</abbr> code ...</var> ?&gt;</code> 
    (<abbr>PHP</abbr> code)</dt>
        <dd>The conformance checker does <em>not</em> support
        checking for PHP source documents.</dd>
    <dt>Other processing instructions</dt>
        <dd>Processing instructions cannot be inserted in an HTML
        document.  Use XML document or insert 
        <code>ProcessingInstruction</code> node by scripting.</dd>
    </dl>

    <p>Web browsers will parse processing instructions as bogus
    comments.  Some legacy Web browsers, such as IE:mac and
    some mobile Web browsers, will display processing instructions
    as string.</p>
  </d:desc>
</d:item>

<d:item name="string after DOCTYPE name"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a bogus string after the document type
  name.</d:message>
</d:item>

<d:item name="string after PUBLIC"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a bogus string after the keyword
  <code>PUBLIC</code>.</d:message>
</d:item>

<d:item name="string after PUBLIC literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a bogus string after the public
  identifier.</d:message>
</d:item>

<d:item name="string after SYSTEM"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a bogus string after the keyword
  <code>SYSTEM</code>.</d:message>
</d:item>

<d:item name="string after SYSTEM literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a bogus string after the system
  identifier.</d:message>
</d:item>

<d:item name="unclosed attribute value"
    modules="HTML::Parser">
  <d:message xml:lang="en">Attribute value is not closed by a quotation
  mark.</d:message>
</d:item>

<d:item name="unclosed comment"
    modules="HTML::Parser">
  <d:message xml:lang="en">Comment is not closed by a string
  <code>--></code>.</d:message>
</d:item>

<d:item name="unclosed DOCTYPE"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>DOCTYPE</code> is not closed by a
  <code>></code> character.</d:message>
</d:item>

<d:item name="unclosed PUBLIC literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">The public identifier literal is not closed by a
  quotation mark.</d:message>
</d:item>

<d:item name="unclosed SYSTEM literal"
    modules="HTML::Parser">
  <d:message xml:lang="en">The system identifier literal is not closed by a
  quotation mark.</d:message>
</d:item>

<d:item name="unclosed tag"
    modules="HTML::Parser">
  <d:message xml:lang="en">Tag is not closed by a <code>></code>
  character.</d:message>
</d:item>

</section>

<section id="html5-parse-errors">
<h2>HTML5 Parse Errors in Tree Construction Stage</h2>

<d:item name="after after frameset"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is a start tag
  <code>&lt;<var>{text}</var>></code> is after the <code>html</code> element
  is closed.</d:message>
  <d:message xml:lang="ja"><code>html</code> 要素が閉じられた後に開始タグ
  <code>&lt;<var>{text}</var>></code> があります。</d:message>
</d:item>

<d:item name="after after frameset:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">There is an end tag
  <code>&lt;/<var>{text}</var>></code> is after the <code>html</code> element
  is closed.</d:message>
  <d:message xml:lang="ja"><code>html</code> 要素が閉じられた後に終了タグ
  <code>&lt;/<var>{text}</var>></code> があります。</d:message>
</d:item>

<d:item name="after body"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>></code> is
  not allowed after the <code>body</code> is closed.</d:message>
</d:item>

<d:item name="after body:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>></code> is
  not allowed after the <code>body</code> is closed.</d:message>
</d:item>

<d:item name="after body:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed
  after the <code>body</code> is closed.</d:message>
</d:item>

<d:item name="after frameset"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>></code> is
  not allowed after the <code>frameset</code> is closed.</d:message>
</d:item>

<d:item name="after frameset:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>></code> is
  not allowed after the <code>frameset</code> is closed.</d:message>
</d:item>

<d:item name="after frameset:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed
  after the <code>frame</code> is closed.</d:message>
</d:item>

<d:item name="after head"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code><var>{text}</var></code> element cannot be
  inserted between <code>head</code> and <code>body</code>
  elements.</d:message>
  <d:desc xml:lang="en">
    <p>A start tag appears after the <code>head</code> element is closed
    but before the <code>body</code> element is opened.
    The document is non-conforming.</p>
  </d:desc>
</d:item>

<d:item name="after html"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>></code> is
  not allowed after the <code>html</code> is closed.</d:message>
  <d:desc xml:lang="en">
    <p>The start 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="after html:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>></code> is
  not allowed after the <code>html</code> is closed.</d:message>
  <d:desc xml:lang="en">
    <p>The 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="after html:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed
  after the <code>html</code> is closed.</d:message>
</d:item>

<d:item name="image"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>image</code> element is
  obsolete.</d:message>
</d:item>

<d:item name="in a:a"
    modules="HTML::Parser">
  <d:message xml:lang="en">Anchor cannot be nested.</d:message>
  <d:desc xml:lang="en">
    <p>HTML <code>a</code> elements cannot be nested.
    The document is non-conforming.</p>

    <p>In the HTML syntax, a start tag of the <code>a</code>
    implies the end tag of any opening <code>a</code> element.</p>
  </d:desc>
</d:item>

<d:item name="in body"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>&gt;</code>
  is not allowed in the <code>body</code> element.</d:message>
  <d:desc xml:lang="en">
    <p>The start or end tag of an element, which 
    cannot be a descendant of <code>body</code> element, appears
    in the input stream while the <code>body</code> element has been opened.
    The document is non-conforming.</p>
  </d:desc>
</d:item>

<d:item name="in body:#eof"
    modules="HTML::Parser">
  <d:message xml:lang="en">Some element is not closed before the end of
  file.</d:message>
</d:item>

<d:item name="in button:button"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>button</code> element cannot be
  nested.</d:message>
</d:item>

<d:item name="in CDATA:#eof"
    modules="HTML::Parser">
  <d:message xml:lang="en">Element is not closed before the end of
  file.</d:message>
</d:item>

<d:item name="in form:form"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;form></code> is
  not allowed in a <code>form</code> element.</d:message>
</d:item>

<d:item name="in frameset"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>></code> is
  not allowed in a <code>framset</code> element.</d:message>
</d:item>

<d:item name="in frameset:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>></code> is
  not allowed in a <code>frameset</code> element.</d:message>
</d:item>

<d:item name="in frameset:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed
  in a <code>frameset</code> element.</d:message>
</d:item>

<d:item name="in head:head"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;head&gt;</code>
  is not allowed in the <code>head</code> element.</d:message>
  <d:desc xml:lang="en">
    <p>There is a start tag <code>&lt;head></code> in the
    <code>&lt;head></code> element.  The document is non-conforming.</p>

    <p>In an HTML document there must not be more than
    one <code>head</code> element, therefore no more than one
    start tag <code>&lt;head></code> can appear in the input stream.</p>
  </d:desc>
</d:item>

<d:item name="in html:#DOCTYPE"
    modules="HTML::Parser">
  <d:message xml:lang="en">A <code>DOCTYPE</code> appears after any
  element or data character has been seen.</d:message>
  <!-- <!DOCTYPE HTML><!DOCTYPE HTML> -->
  <!-- <html><!DOCTYPE HTML> -->
  <d:desc xml:lang="en">
    <p>A <code>DOCTYPE</code> appears after any element or data character
    has been seen.  The document is non-conforming.</p>
    
    <p>The <code>DOCTYPE</code> must be placed before any
    tag, reference, or data character.  Only white space characters
    and comments can be inserted before the <code>DOCTYPE</code>.</p>
  </d:desc>
</d:item>

<d:item name="in nobr:nobr"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>nobr</code> element cannot be
  nested.</d:message>
</d:item>

<d:item name="in noscript"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code><var>{text}</var></code> element is not
  allowed in a <code>noscript</code> element in the
  <code>head</code> element.</d:message>
</d:item>

<d:item name="in noscript:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">An end tag <code>&lt;/<var>{text}</var>></code>
  appers before the <code>noscript</code> element is closed.</d:message>
</d:item>

<d:item name="in noscript:#eof"
    modules="HTML::Parser">
  <d:message xml:lang="en">A <code>noscript</code> element is not closed
  before the end of file.</d:message>
</d:item>

<d:item name="in noscript:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed
  in a <code>noscript</code> element in the <code>head</code>
  element.</d:message>
</d:item>

<d:item name="in PCDATA:#eof"
    modules="HTML::Parser">
  <d:message xml:lang="en">Element is not closed before the end of
  file.</d:message>
</d:item>

<d:item name="in select"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>&gt;</code>
  is not allowed in a <code>select</code> element.</d:message>
</d:item>

<d:item name="in select:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>&gt;</code>
  is not allowed in a <code>select</code> element.</d:message>
</d:item>

<d:item name="in table"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>&gt;</code>
  is not allowed in a <code>table</code> element.</d:message>
  <d:desc xml:lang="en">
    <p>The start or end tag of an element, which
    cannot be a child of <code>table</code> element, appears
    in the input stream while the <code>table</code> element has been opened
    but no other element has been opened.  The document is non-conforming.</p>

    <p>In <code>table</code>, only table related elements
    are allowed; any other element must be contained in
    <code>td</code> or <code>th</code> element to form 
    a part of the table, or <code>caption</code> element to create
    a table caption.</p>
  </d:desc>
</d:item>

<d:item name="in table:/"
    modules="HTML::Parser">
  <d:message xml:lang="en">End tag <code>&lt;/<var>{text}</var>&gt;</code>
  is not allowed in a <code>table</code> element.</d:message>
</d:item>

<d:item name="in table:#text"
    modules="HTML::Parser">
  <d:message xml:lang="en">Non‐white‐space character is not allowed within 
  the <code>table</code> element, outside of the caption and cells.</d:message>
  <d:desc xml:lang="en">
    <p>A non‐white‐space character appears in <code>table</code>.
    The document is non-conforming.</p>

    <p>In <code>table</code>, only table related elements
    are allowed; any other element and data character must be contained in
    <code>td</code> or <code>th</code> element to form 
    a part of the table, or <code>caption</code> element to create
    a table caption.</p>
  </d:desc>
</d:item>

<d:item name="isindex"
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>isindex</code> element is
  obsolete.</d:message>
</d:item>

<d:item name="missing start tag:tr"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag of <code>tr</code>
  element is missing.</d:message>
  <d:desc>
    <p>Start tag of a <code>tr</code> element, which is <em>not</em>
    optional, is missing.  The document is non-conforming.</p>

    <p>In a table section, a <code>&lt;tr></code> start tag
    must occur before any <code>&lt;td></code> or
    <code>&lt;th></code> start tag.  Though the HTML5 parser
    implies the <code>&lt;tr></code> start tag before
    these start tags, it must be explicitly specified.</p>
  </d:desc>
</d:item>

<d:item name="no DOCTYPE"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">This document does not start with a
  <code>DOCTYPE</code>.</d:message>
  <d:desc>
    <p>The document does not start with a <code>DOCTYPE</code>.
    The document is non-conforming.</p>

    <p>An HTML document must start by a <code>DOCTYPE</code>:
      <pre class="html example"><code>&lt;!DOCTYPE HTML></code></pre>
    </p>

    <p>Only white space characters and comments are allowed
    before the <code>DOCTYPE</code>.  XML declaration is <em>not</em>
    allowed in HTML document.</p>
  </d:desc>
</d:item>

<d:item name="not closed"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">Element <code><var>{text}</var></code> is not
  closed.</d:message>
  <d:desc>
    <p>End tag of an element is not found before, for example,
    an end tag of another element appears or
    the end of the document.  The document is non-conforming.</p>

    <p>Only <code>body</code>, <code>colgroup</code>, <code>dd</code>,
    <code>dt</code>, <code>head</code>, <code>html</code>, <code>li</code>,
    <code>ol</code>, <code>option</code>, <code>optgroup</code>, 
    <code>p</code>, <code>rb</code>, <code>rp</code>, <code>rt</code>,
    <code>tbody</code>, <code>td</code>, <code>tfoot</code>,
    <code>th</code>, <code>thead</code>, <code>tr</code>,
    <code>ul</code> end tag can be omitted in HTML documents.
    For any element except for void element, there must be an explicit
    end tag.</p>

    <dl class="switch">
    <dt>HTML <code>canvas</code> element</dt>
      <dd>Though the element is void in earlier versions of Safari,
      the <code>canvas</code> element is <em>no</em> longer
      defined as empty.  There must be an end tag
      <code class="html example">&lt;/canvas></code>.</dd>
    </dl>

    <p>Note that misnesting tags, such as 
    <code class="bad example">&lt;a>&lt;b>&lt;/a>&lt;/b></code>, are not
    allowed and they also cause this error.</p>
  </d:desc>
</d:item>

<d:item name="not first start tag"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">This <code>&lt;html></code> tag is not
  the first start tag.</d:message>
  <d:desc>
    <p>There is a start tag of the <code>html</code> element
    that it not the first start tag in the input stream.
    The document is non-conforming.</p>

    <p>In an HTML document, there cannot be more than one
    <code>html</code> element and therefore there cannot be
    more than one <code>&lt;html></code> tag.  In addition,
    nothing can be placed before the <code>&lt;html></code> tag
    except a <code>DOCTYPE</code>, white space characters, 
    and comments.</p>
  </d:desc>
</d:item>

<d:item name="not HTML5"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">This document is written in an old version of 
  HTML.</d:message>
  <d:desc xml:lang="en">
    <p>The document contains a <code>DOCTYPE</code> declaration
    that is different from HTML5 <code>DOCTYPE</code> (i.e. 
    <code class="example html">&lt;!DOCTYPE HTML&gt;</code>).
    The document is non‐conforming.</p>

    <p>The document might or might not be conformant to
    some version of HTML.  However, conformance to any HTML
    specification other than HTML5 provides for no practical
    convenience, since Web borwsers will parse any
    HTML document (roughly) as defined in HTML5.</p>
  </d:desc>
</d:item>

<d:item name="start tag not allowed"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">Start tag <code>&lt;<var>{text}</var>></code> is
  not allowed here.</d:message>
</d:item>

<d:item name="unmatched end tag"
    class="parse-error"
    modules="HTML::Parser">
  <d:message xml:lang="en">Element <code><var>{text}</var></code> is not
  opened.</d:message>
  <d:desc>
    <p>An end tag appears though no element with the same name
    has been opened.  The document is non-conforming.</p>

    <p>For any end tag in HTML document, there must be a
    corresponding start tag.</p>

    <dl class="switch">
    <dt>HTML <code>base</code>, <code>basefont</code>,
    <code>bgsound</code>, <code>br</code>, <code>col</code>,
    <code>embed</code>, <code>frame</code>, <code>hr</code>,
    <code>image</code>, <code>img</code>, <code>input</code>,
    <code>isindex</code>, <code>link</code>, <code>meta</code>,
    <code>param</code>, <code>spacer</code>, or <code>wbr</code> element</dt>
      <dd>End tag is not allowed for these elements, since
      those content must always be empty.  Remove end tag.</dd>
    <!-- keygen -->
    <!-- command, event-source, nest, source -->
    </dl>
  </d:desc>
</d:item>

<d:item name="XSLT-compat" 
    modules="HTML::Parser">
  <d:message xml:lang="en">The <code>DOCTYPE</code> legacy string is
  used.</d:message>
  <d:message xml:lang="ja"><code>DOCTYPE</code>
  遺物文字列が使われています。</d:message>
  <d:desc xml:lang="en">
    <p>The <code>DOCTYPE</code> with the <code>DOCTYPE</code> legacy
    string, i.e.
    <code class="html bad example">&lt;!DOCTYPE HTML PUBLIC "XSLT-compat"></code>
    is used.</p>

    <p>The <code>DOCTYPE</code> legacy string should not be used for documents
    <em>not</em> generated from XSLT transformation process.  It is allowed
    only to enable to use XSLT style sheets with the HTML output mode, which
    does not support generation of the <code>DOCTYPE</code> with no
    <code>PUBLIC</code>
    identifier.  For other purposes, the <code>DOCTYPE</code> legacy
    string, i.e. <code class="html bad example">PUBLIC "XSLT-compat"</code>,
    is useless and should not be used.</p>
  </d:desc>
</d:item>

</section>

<section id="element-content-model-errors">
<h2>Element Content Model Errors</h2>

<d:item name="basehref after URL attribute"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>base</code> element with the 
  <code>href</code> attribute specified cannot be placed after
  any attribute with a URL.</d:message>
</d:item>

<d:item name="basetarget after hyperlink"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>base</code> element with the
  <code>target</code> attribute specified cannot be placed after
  any element that defines a hyperlink.</d:message>
</d:item>

<d:item name="character not allowed"
    modules="ContentChecker::HTML RDFXML">
  <d:message xml:lang="en">Data character is not allowed in this
  context.</d:message>
  <d:desc xml:lang="en">
    <p>A data character appears where it is not allowed in this
    context.  The document is non-conforming.</p>

    <p>Possible causes:
      <ul>
      <li><p>A data character cannot be a child
      of certain sectioning elements such as <code>body</code>,
      <code>section</code>, and <code>blockquote</code>.</p>

      <p>Any inline-level content must be put
      in e.g. paragraph element such as <code>p</code>.</p></li>
      <li><p>Though some elements such as <code>div</code>,
      <code>li</code>, and <code>td</code> allow
      <em>either one</em> of block-level or inline-level content
      is allowed.  If there is a block-level content, 
      any inline-level content must be put
      in e.g. paragraph element such as <code>p</code>.</p></li>
      </ul>
    </p>
  </d:desc>
</d:item>

<d:item name="character not allowed:empty"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed in
  an empty element.</d:message>
</d:item>

<d:item name="character not allowed:atom|PersonConstruct"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed in
  Person construct.</d:message>
</d:item>

<d:item name="character not allowed:atom|TextConstruct"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Non‐white‐space characters are not allowed in
  Text construct.</d:message>
</d:item>

<d:item name="child element missing"
    modules="ContentChecker::HTML ContentChecker::Atom">
  <d:message xml:lang="en">There must be an element
  <code><var>{text}</var></code> as a child of this element.</d:message>
  <d:desc xml:lang="en">
    <p>The content model of the element is so defined that it
    must contain a <code><var>$0</var></code> child element.
    The document is non-conforming.</p>

    <dl class="switch">
    <dt>HTML <code>head</code> element</dt>
      <dd>There must be a <code>title</code> child element.</dd>
    <dt>HTML <code>html</code> element</dt>
      <dd>There must be a <code>head</code> child element followed
      by a <code>body</code> element.</dd>
    <dt>HTML <code>tr</code> element</dt>
      <dd><a href="#child-element-missing:td%7Cth">There must be
      one or more <code>td</code> or <code>th</code> child element.</a></dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="child element missing:td|th"
    class="content-model-error">
  <d:message xml:lang="en">There must be a <code>td</code>
  or <code>th</code> element as a child of this element.</d:message>
  <d:desc xml:lang="en">
    <p>The <code>tr</code> element must contain at least one
    <code>td</code> or <code>th</code> child element.  The document
    is non-conforming.</p>
  </d:desc>
</d:item>

<d:item name="child element missing:atom"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There must be an element
  <code><var>{text}</var></code> in the Atom namespace as a child of this
  element.</d:message>
</d:item>

<d:item name="child element missing:atom:link:alternate"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There must be an Atom <code>link</code> element
  whose <code>rel</code> attribute is set to <code>alternate</code> as a
  child of this element.</d:message>
</d:item>

<d:item name="child element missing:atom:link:self"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There should be an Atom <code>link</code> element
  whose <code>rel</code> attribute is set to <code>self</code> as a
  child of this element.</d:message>
</d:item>

<d:item name="element missing:hn"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There must be at least one 
  <code>h<var>n</var></code> element descendant.</d:message>
</d:item>

<d:item name="element not allowed"
    modules="ContentChecker::HTML ContentChecker::Atom RDFXML">
  <d:message xml:lang="en">This element is not allowed in this 
  context.</d:message>
  <d:desc xml:lang="en">
    <p>An element appears where it is not allowed.  The document
    is non-conforming.</p>

    <p>Possible causes:
      <dl class="switch">
      <dt>If the element with the error is an inline-level element,
      such as <code>a</code>, <code>progress</code>, or <code>img</code></dt>
          <dd><p>An inline-level element cannot be a child
          of certain sectioning elements such as <code>body</code>,
          <code>section</code>, and <code>blockquote</code>.</p>

          <p>Any inline-level content must be put
          in e.g. paragraph element such as <code>p</code>.</p></dd>
      <dt>If it is a block-level elements, such as <code>aside</code>,
      <code>div</code>, <code>h<var>n</var></code>,
      <code>p</code>, or <code>section</code></dt>
          <dd><dl class="switch">
              <dt>If the parent element is <code>div</code>,
              <code>li</code>, <code>td</code>, or <code>th</code></dt>
              <!-- @@ TODO: more... -->
                  <!-- @@ TODO: <p><ul><li><p> -->
                  <dd><p>The parent element allows <em>either</em>
                  block-level or inline-level content.  If there is a
                  block-level content, any inline-level content must be
                  put in e.g. paragraph element such as <code>p</code>.</p>
                  <p>For example, an HTML document fragment
                  <code class="html bad example">&lt;div>&lt;p>Hello!&lt;/p> World!&lt;/div></code>
                  is non-conforming, since a word <q>World!</q> does not belong
                  to any paragraph.  (If not part of any paragraph, what is
                  it!?)  A conforming example would be:
                    <pre class="html example"><code>&lt;div>&lt;p>Hello!&lt;/p> &lt;p>World!&lt;/p>&lt;/div></code></pre>
                  </p></dd>
              <dt>If the parent element does <em>not</em> allow 
              block-level elements as content</dt>
                  <dd>The element is not allowed to be inserted here.
                  For example, a <code>div</code> element cannot be 
                  a child of an <code>h1</code> element.</dd>
          </dl></dd>
      <dt>If the element with the error is a <code>noscript</code> element</dt>
          <dd>The <code>noscript</code> element is allowed only in the context
          where a block-level or inline-level content is expected
          and in the <code>head</code> element.
          It cannot be used in e.g. <code>ul</code>, <code>table</code>,
          or <code>select</code>.</dd>
      <dt>If the element with the error is <code>blink</code>,
      <code>center</code>, or <code>marquee</code> element</dt>
          <dd>These elements are not part of the HTML standard.
          Use CSS for styling control.</dd>

      <dt><code>button</code>, <code>datalist</code>,
      <code>fieldset</code>, <code>form</code>,
      <code>input</code>, <code>label</code>,
      <code>optgroup</code>, <code>option</code>, <code>output</code>,
      <code>rb</code>, <code>rp</code>, <code>rt</code>, <code>ruby</code>,
      <code>textarea</code>, or <code>textarea</code> element</dt>
      <!-- rbc, rtc ? -->
          <dd>These elements are intentionally not supported by the conformance
          checker <em>yet</em>.</dd>
      </dl>
    </p>
  </d:desc>
</d:item>

<d:item name="element not allowed:area"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">An <code>area</code> element cannot be used
  outside of a <code>map</code> element.</d:message>
</d:item>

<d:item name="element not allowed:base"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">There is another <code>base</code>
  element.</d:message>
</d:item>

<d:item name="element not allowed:datatemplate"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">In a <code>datatemplate</code> element, only
  <code>rule</code> elements are allowed.</d:message>
</d:item>

<d:item name="element not allowed:details legend"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">In a <code>details</code> element, only at the
  beginning of the element a <code>lengend</code> element
  may be used.</d:message>
</d:item>

<d:item name="element not allowed:empty"
    modules="ContentChecker::HTML ContentChecker::Atom">
  <d:message xml:lang="en">Elements are not allowed in an empty
  element.</d:message>
</d:item>

<d:item name="element not allowed:figure legend"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">In a <code>figure</code> element, only at the
  beginning or only at the end of the element a <code>lengend</code> element
  may be used.</d:message>
</d:item>

<d:item name="element not allowed:flow"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed where flow
  content is expected.</d:message>
</d:item>

<d:item name="element not allowed:flow style"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">A <code>style</code> element without
  <code>scoped</code> attribute is not allowed in this context.</d:message>
</d:item>

<d:item name="element not allowed:head noscript"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed in a
  <code>noscript</code> element in the <code>head</code> element.</d:message>
</d:item>

<d:item name="element not allowed:head style"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">A <code>style</code> element with
  <code>scoped</code> attribute is not allowed in the <code>head</code>
  element.</d:message>
</d:item>

<d:item name="element not allowed:head title"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">There is another <code>title</code>
  element.</d:message>
</d:item>

<d:item name="element not allowed:minus"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed in this
  context.</d:message>
</d:item>

<d:item name="element not allowed:meta charset"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The character encoding declaration is not the
  first child element in the <code>head</code> element.</d:message>
  <d:message xml:lang="ja">文字符号化宣言が <code>head</code> 
  要素の最初の子要素ではありません。</d:message>
  <d:desc xml:lang="en">
    <p>The character encoding declaration
    (<code class="html example">&lt;meta charset="<var>...</var>"></code> or
    <code class="html example">&lt;meta http-equiv=Content-Type content="text/html; charset=<var>...</var>"></code>
    must be the first child element in the <code>head</code> element.</p>

    <p>The character encoding declaration have to occur near the beginning
    of the document to ensure that Web browsers can be determine the
    character encoding of the document.</p>

    <p>The <code>title</code> element and other metadata elements must
    appear after any character encoding declaration is processed.</p>
  </d:desc>
</d:item>

<d:item name="element not allowed:metadata"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed where metadata
  content is expected.</d:message>
</d:item>

<d:item name="element not allowed:phrasing"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed where phrasing
  content is expected.</d:message>
</d:item>

<d:item name="element not allowed:root"
    modules="ContentChecker">
  <d:message xml:lang="en">This element is not allowed as the root
  element of a document.</d:message>
  <d:desc xml:lang="en">
    <p>An element that is not allowed as the root element
    is used as the root element of the document.  The document is
    non-conforming, as far as the conformance checker can tell.</p>

    <dl class="switch">
    <dt><code>html</code> element in an XHTML document</dt>
        <dd><p>In <abbr>XHTML</abbr> document, the root <code>html</code>
        element must have an <code>xmlns</code> attribute as:
          <pre class="xml example"><code>&lt;html xmlns="http://www.w3.org/1999/xhtml"></code></pre></p></dd>
    <dt><code>rss</code> element</dt>
        <dd><p>The document is written in some version of RSS.</p>
        <p>The conformance checker does not support any version
        of RSS.  Use Atom 1.0 for feed documents.</p></dd>
    <dt><code>feed</code> element</dt>
        <dd><p>The Atom <code>feed</code> element must be
        in the <code>http://www.w3.org/2005/Atom</code>
        namespace as:
          <pre class="xml example"><code>&lt;feed xmlns="http://www.w3.org/2005/Atom"></code></pre>
        </p>
        <p>The conformance checker does not support Atom 0.3.
        Use Atom 1.0 for feed documents.</p></dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="element not allowed:root:xml"
    modules="ContentChecker">
  <d:message xml:lang="en">This element is not allowed as the root element
  of an XML document.</d:message>
</d:item>

<d:item name="element not allowed:ruby base"
    modules="ContentChecker">
  <d:message xml:lang="en">This element is not allowed in the <code>ruby</code>
  element.</d:message>
</d:item>

<d:item name="element not allowed:text"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This element is not allowed in this
  context.</d:message>
</d:item>

<d:item name="element not allowed:atom|content"
    modules="ContentChecker::Atom">
  <d:message xml:lang="en">This element is not allowed in an Atom
  <code>content</code> element.</d:message>
</d:item>

<d:item name="element not allowed:atom|PersonConstruct"
    modules="ContentChecker::Atom">
  <d:message xml:lang="en">This element is not allowed in Person
  construct.</d:message>
</d:item>

<d:item name="element not allowed:atom|TextConstruct"
    modules="ContentChecker::Atom">
  <d:message xml:lang="en">This element is not allowed in Text
  construct.</d:message>
</d:item>

<d:item name="element not defined"
    modules="ContentChecker">
  <d:message xml:lang="en">This element is not defined.</d:message>
  <d:message xml:lang="ja">この要素は定義されていません。</d:message>
  <d:desc xml:lang="en">
    <p>The element is not one of elements allowed
    in the latest version of relevant specifications.</p>

    <p>The element cannot be used.</p>

    <dl class="switch">
    <dt><code>event-source</code> element</dt>
        <dd>The element was renamed as <em><code>eventsource</code>
        element</em> (no hyphen).</dd>
    <dt><code>m</code> element</dt>
        <dd>The element was renamed as <em><code>mark</code>
        element</em>.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="no significant content"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">No significant content is contained
  in this element.</d:message>
</d:item>

<d:item name="no significant content before"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There is no significant content
  before this element.</d:message>
</d:item>

<d:item name="no significant content at the end"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">No significant content is contained
  at the end of this element.</d:message>
</d:item>

<d:item name="ps element missing"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There is no <code><var>{text}</var></code>
  element before this element.</d:message>
  <d:desc xml:lang="en">
    <p>There must be an element before another element, but there
    is not.  The document is non-conforming.</p>

    <p>For example, there must be a <code>dt</code> element
    before any <code>dd</code> element.</p>
  </d:desc>
</d:item>

<d:item name="rp:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The content of a <code>rp</code> element must
  be a parenthesis.</d:message>
</d:item>

</section>

<section id="attribute-errors">
<h2>Attribute Errors</h2>

<d:item name="attribute missing"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Required attribute <code><var>{text}</var></code>
  is not specified.</d:message>
  <d:desc>
    <p>A required attribute is not specified.  The document
    is non-conforming.</p>

    <p>Some attribute is defined as <i>required</i>.
    Without required attributes specified, user agents 
    cannot provide full functionality of the element to the user.</p>

    <dl class="switch">
    <dt>HTML <code>img</code> element</dt>
        <dd>The <code>src</code> attribute must be specified.
        Additionally, the <code>alt</code> attribute must be specified
        in many cases.</dd>
    <dt>HTML <code>link</code> element</dt>
        <dd>The <code>rel</code> attribute must be specified.
        Note that the <code>rev</code> attribute is obsolete.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="attribute missing:data|type"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">For an <code>object</code> at least one of
  <code>data</code> and <code>type</code> attributes must be 
  specified.</d:message>
</d:item>

<d:item name="attribute missing:href|target"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">For a <code>base</code> element, at least one of
  <code>href</code> and <code>target</code> attributes must be
  specified.</d:message>
</d:item>

<d:item name="attribute missing:name|http-equiv"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">For a <code>meta</code> element with the
  <code>content</code> attribute specified, exactly one of
  <code>name</code> and <code>http-equiv</code> attributes must be
  specified.</d:message>
</d:item>

<d:item name="attribute missing:name|http-equiv|charset"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">For a <code>meta</code> element, exactly one of
  <code>name</code>, <code>http-equiv</code>, and <code>charset</code>
  attributes must be specified.</d:message>
</d:item>

<d:item name="attribute not allowed"
    modules="ContentChecker::HTML RDFXML">
  <d:message xml:lang="en">Attribute
  <code><var>{local-name}</var></code> is not allowed for
  <code><var>{element-local-name}</var></code> element.</d:message>
  <d:desc xml:lang="en">
    <p>An attribute is specified where it is not allowed.
    The document is non-conforming.</p>

    <dl>
    <dt>HTML <code>meta</code> element</dt>
        <dd>For HTML <code>meta</code> element, <em>only one</em> of
        <code>name</code>, <code>http-equiv</code>, or <code>charset</code>
        attribute is allowed.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="attribute not allowed:ismap"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>ismap</code> attribute may only be
  used for the image contained in an <code>a</code> element.</d:message>
</d:item>

<d:item name="attribute not defined"
    modules="ContentChecker">
  <d:message xml:lang="en">This attribute is not defined.</d:message>
  <d:message xml:lang="ja">この属性は定義されていません。</d:message>
  <d:desc xml:lang="en">
    <p>The attribute is not one of attributes allowed for the element
    in the latest version of relevant specifications.</p>

    <p>The attribute cannot be used.</p>

    <dl class="switch">
    <dt><code>align</code> attribute (various HTML elements)</dt>
    <dt><code>border</code> attribute (various HTML elements)</dt>
      <dd>These attributes are no longer part of HTML.  You can use CSS
      properties to control the presentation of the element.</dd>
    <dt><code>autosubmit</code> attribute (<code>menu</code> element)</dt>
      <dd>The attribute was part of HTML5 draft but then dropped.
      Similar functionality can be implemented by scripts.</dd>
    <dt><code>language</code> attribute (<code>script</code> element)</dt>
      <dd>The attribute is no longer the standard way to specify the
      scripting language.  If you are using JavaScript, then no explicit
      specification of the scripting language is necessary, so you can
      write the element like:
        <p><code class="html example code">&lt;script><br/><!--
        --> /* JavaScript code */<br/><!--
        -->&lt;/script></code></p>
      If you are using different scripting language from JavaScript, or 
      you want to declare the scripting language explicitly, you should
      use the <code>type</code> attribute, as follows:
        <dl class="switch">
        <dt>JavaScript</dt>
          <dd>Use
          <code class="html example">&lt;script type="text/javascript"></code>.</dd>
        <dt>VBScript</dt>
          <dd>Use
          <code class="html example">&lt;script type="text/vbscript"></code>.</dd>
        </dl>
      </dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="in HTML:xml:lang"
    modules="ContentChecker::XML">
  <d:message xml:lang="en">The <code>xml:lang</code> attribute in HTML
  document is ignored.</d:message>
  <d:desc xml:lang="en">
    <p>The <code>xml:lang</code> attribute does not have an effect in
    HTML document.</p>

    <p>The <code>xml:lang</code> attribute is only applicable to XML
    documents.  In HTML document, it is only allowed to ease migration
    from XML.</p>

    <p>To specify natural language information in HTML document,
    use <code>lang</code> attribute instead.</p>

    <p>XHTML 1.0 Appendix C was encouraged to specify both
    <code>lang</code> and <code>xml:lang</code> attributes with
    the same value.  Such a duplication has <em>no effect</em> in practice.
    Use only one of <code>lang</code> (in HTML) or <code>xml:lang</code> (in
    XML).</p>

    <!-- @@ ISSUE: xml:lang in non-HTML element in DOM5 HTML created
         from an HTML document? -->
  </d:desc>
</d:item>

<d:item name="in XML:charset"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>charset</code> attribute is not 
  allowed in XML document.</d:message>
  <d:desc>
    <p>The <code>charset</code> attribute of a
    <code>meta</code> element is not allowed in XML document.
    The document is non-conforming.</p>

    <p>To specify the character encoding used for serialization,
    if necessary, use XML declaration instead:
      <pre class="xml example"><code>&lt;?xml version="1.0" encoding="<var>encoding-name</var>"?></code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="in XML:noscript"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">A <code>noscript</code> element cannot be 
  used in XML document.</d:message>
</d:item>

<d:item name="in XML:xml:lang"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>xml:lang</code> attribute in no namespace
  is only allowed in HTML document.</d:message>
  <d:message xml:lang="ja">名前空間に属さない <code>xml:lang</code> 
  属性が認められているのは HTML 文書中だけです。</d:message>
</d:item>

<d:item name="in XML:xmlns"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>xmlns</code> attribute 
  in the <code>null</code> namespace is not allowed in
  XHTML document.  The document is non-conforming.</d:message>
  <d:desc>
    <p>The <code>xmlns</code> attribute in the <code>null</code>
    namespace is not allowed in XHTML document.</p>

    <p>This error should not occur in conformance-checking of
    static documents.</p>
  </d:desc>
</d:item>

<d:item name="xml:lang not allowed"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>xml:lang</code> attribute is only allowed
  when the <code>lang</code> attribute is specified.</d:message>
  <d:message xml:lang="ja"><code>xml:lang</code> 属性を指定できるのは
  <code>lang</code> 属性が指定されている時だけです。</d:message>
</d:item>

</section>

<section id="attribute-value-errors">
<h2>Attribute Value Errors</h2>

<d:item name="boolean:invalid"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Attribute value <code><var>{@}</var></code>
  is not allowed.  It must be an empty string or a string
  <code><var>{local-name}</var></code>.</d:message>
</d:item>

<d:item name="char:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value must be exactly one
  character.</d:message>
</d:item>

<d:item name="charref in charset"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">A character reference cannot be used to
  represent a character encoding name.</d:message>
</d:item>

<d:item name="charset:not preferred"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Character encoding name
  <code><var>{value}</var></code> is not the preferred name of that
  character encoding.</d:message>
</d:item>

<d:item name="charset:not registered"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Character encoding name
  <code><var>{value}</var></code> is not a registered name.</d:message>
  <d:desc xml:lang="en">
    <p>The specified character encoding name is not registered to
    <abbr>IANA</abbr>.  Use of registered character encoding name
    is a good practice to facilitate interoperability.</p>

    <dl class="switch">
    <dt><code>EUC-TW</code></dt>
      <dd><code>EUC-TW</code> is not registered.  Unfortunately, there
      is no registered name for that character encoding.  Use
      Big5 encoding with character encoding name <code>Big5</code> 
      if it is enough to represent the document.</dd>
    <dt><code>ISO-2022-JP-1</code></dt>
      <dd><code>ISO-2022-JP-1</code> is not registered, nevertheless
      this character encoding name is documented in 
      <a href="urn:ietf:rfc:2237"><abbr>RFC</abbr> 2237</a>.  Use
      <code>ISO-2022-JP-2</code> instead, since that character encoding
      is a superset of ISO-2022-JP-1.</dd>
    <dt><code>ISO-2022-JP-3</code>, <code>ISO-2022-JP-3-plane1</code></dt>
      <dd>These names are not registered and obsoleted in favor of
      <code>ISO-2022-JP-2004</code> and
      <code>ISO-2022-JP-2004-plane1</code>.</dd>
    <dt><code>ISO-2022-JP-2003</code>,
    <code>ISO-2022-JP-2003-plane1</code></dt>
      <dd>These names are not registered and corrected to
      <code>ISO-2022-JP-2004</code> and
      <code>ISO-2022-JP-2004-plane1</code>.</dd>
    <dt><code>ISO-2022-JP-2004</code>,
    <code>ISO-2022-JP-2004-plane1</code></dt>
      <dd>These names are not registered.  Unfortunately, there is 
      no registered name for these character encodings.</dd>
    <dt><code>UTF-8N</code></dt>
      <dd><code>UTF-8N</code> is not registered.  Character encoding
      name <code>UTF-8</code> represents UTF-8 encoding with or
      without <abbr>BOM</abbr>.</dd>
    </dl>

    <p><strong>WARNING</strong>: This error might be raised for
    a registered character encoding name, since the character encoding
    name database of the conformance checker is not complete yet.</p>
  </d:desc>
</d:item>

<d:item name="charset:private"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Character encoding name
  <code><var>{value}</var></code> is a private name.</d:message>
  <d:desc xml:lang="en">
    <p>The specified character encoding name is a private name and
    not registered to <abbr>IANA</abbr>.  Use of registered character
    encoding name is a good practice to facilitate interoperability.</p>

    <dl class="switch">
    <dt><code>x-euc-jp</code></dt>
      <dd>Use <code>EUC-JP</code> for the Japanese <abbr>EUC</abbr>
      character encoding.</dd>
    <dt><code>x-sjis</code></dt>
      <dd>Use <code>Shift_JIS</code> for standard Shift encoding scheme of
      <abbr>JIS</abbr> coded character set, or <code>Windows-31J</code>
      for Microsoft standard character set as implemented by
      Microsoft Windows.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="charset:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value <code><var>{value}</var></code>
  is syntactically not a character encoding name.</d:message>
  <d:desc xml:lang="en">
    <p>The attribute value must be a character encoding name.  However,
    the specified value is not a character encoding name syntactically.
    The document is non‐conforming.</p>
    <p>Character encoding name is a string of <abbr>ASCII</abbr>
    printable characters, up to 40 characters.</p>
  </d:desc>
</d:item>

<d:item name="color:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value is not a color
  name or hexadecimal color number.</d:message>
</d:item>

<d:item name="coords:number not 3"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>coords</code> attribute have to
  contain three (3) numbers (specified:
  <code><var>{text}</var></code>).</d:message>
</d:item>

<d:item name="coords:number not 4"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>coords</code> attribute have to
  contain four (4) numbers (specified:
  <code><var>{text}</var></code>).</d:message>
</d:item>

<d:item name="coords:number lt 6"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>coords</code> attribute have to
  contain more than or equal to six (6) numbers (specified:
  <code><var>{text}</var></code>).</d:message>
</d:item>

<d:item name="coords:number not even"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>coords</code> attribute have to
  contain even number of numbers (specified:
  <code><var>{text}</var></code>).</d:message>
</d:item>

<d:item name="coords:out of range"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value <code><var>{value}</var></code>
  is out of range.</d:message>
</d:item>

<d:item name="coords:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value is not valid.</d:message>
</d:item>

<d:item name="datetime:bad year"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Year number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad month"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Month number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad day"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Day number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad hour"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Hour number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad minute"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Minute number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad second"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Second number is out of range.</d:message>
</d:item>

<d:item name="datetime:bad timezone hour"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Hour number of the timezone component is out of
  range.</d:message>
</d:item>

<d:item name="datetime:bad timezone minute"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Minute number of the timezone component is out of
  range.</d:message>
</d:item>

<d:item name="datetime:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not a datetime.</d:message>
</d:item>

<d:item name="dateortime:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The value is not a date or time.</d:message>
</d:item>

<d:item name="enumerated:invalid"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">This attribute only allow a limited set of 
  values and the specified value <code><var>{@}</var></code> is not one 
  of them.</d:message>
  <d:desc xml:lang="en">
    <p>For this attribute only several values are allowed and the
    value of the attribute is not one of them.  The document
    is non-conforming.</p>

    <dl>
    <dt>HTML <code>meta</code> element, <code>http-equiv</code> attribute</dt>
        <dd><p>Only values <code>Default-Style</code> and <code>Refresh</code>
        are allowed.</p>
        <p>Value <code>Content-Type</code> is obsolete; for charset
        declaration, the <code>charset</code> attribute can be used as:
        <pre class="html example"><code>&lt;meta charset="<var>charset-name</var>"></code></pre>
        ... where <var>charset-name</var> is a name of the character encoding
        of the document, such as <code>utf-8</code>.</p>
        <p>Values <code>Content-Style-Type</code> and
        <code>Content-Script-Type</code> are currently not allowed.</p>
        <p>Value <code>Keywords</code> is not allowed.  Use
        <code>name</code> attribute instead of <code>http-equiv</code>
        attribute.</p>
        <p>Values <code>Expires</code>, <code>Pragma</code>,
        and <code>Cache-Control</code> are not allowed;
        use <em>real</em> HTTP header fields for cache control.</p></dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="enumerated:invalid:http-equiv:content-type"
    class="attribute-value-error">
  <d:message xml:lang="en">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.</d:message>
  <d:desc xml:lang="en">
    <p>Old 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 in use.  The document is non‐conforming.</p>

    <p>The new character encoding declaration syntax is:
      <pre class="html example"><code>&lt;meta charset="<var>charset-name</var>"></code></pre>
    </p>
  </d:desc>
</d:item>

<d:item name="enumerated:non-conforming"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Attribute value <code><var>{@}</var></code>
  is not allowed.</d:message>
</d:item>

<d:item name="duplicate http-equiv"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">There is another pragma
  <code><var>{value}</var></code>.</d:message>
</d:item>

<d:item name="duplicate ID"
    class="attribute-value-error"
    modules="ContentChecker::XML ContentChecker::HTML">
  <d:message xml:lang="en">This identifier has already been
  assigned to another element.</d:message>
  <!-- @@ <id=a xml:id=a>? -->
</d:item>

<d:item name="duplicate token"
    modules="ContentChecker::HTML HTML::Table">
  <d:message xml:lang="en">The token <code><var>{value}</var></code>
  appears in the attribute value twice.</d:message>
</d:item>

<d:item name="empty attribute value"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is empty.</d:message>
  <d:message xml:lang="ja">属性値が空です。</d:message>
</d:item>

<d:item name="empty style sheet title"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The value of the <code>title</code> attribute
  is empty.</d:message>
  <d:message xml:lang="ja"><code>title</code> 属性の値が空です。</d:message>
  <d:desc xml:lang="en">
    <p>The <code>title</code> attribute value of the <code>link</code>
    element that defines an alternate style sheet is an empty value.</p>

    <p>A <code>link</code> element whose <code>rel</code> attribute
    is <code>alternate stylesheet</code> defines an alternate style sheet.
    An alternate style sheet must be associated with a name using the
    <code>title</code> attribute.  The name cannot be empty.</p>
  </d:desc>
</d:item>

<d:item name="float:out of range"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value is out of range.</d:message>
</d:item>

<d:item name="float:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not a real
  number.</d:message>
</d:item>

<d:item name="fragment points itself"
    modules="ContentChecker">
  <d:message xml:lang="en">A fragment identifier references the element
  itself.</d:message>
</d:item>

<d:item name="fragment points nothing"
    modules="ContentChecker">
  <d:message xml:lang="en">A fragment identifier references no
  node.</d:message>
</d:item>

<d:item name="hashref:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">A hash−name reference must start with a
  <code>#</code> character.</d:message>
</d:item>

<d:item name="id ne name"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The <code>id</code> attribute value is 
  different from the <code>name</code> attribute value.</d:message>
</d:item>

<d:item name="integer:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not an integer.</d:message>
</d:item>

<d:item name="link type:bad context"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The link type <code><var>{value}</var></code>
  cannot be specified for this element.</d:message>
  <d:desc xml:lang="en">
    <p>The specified link type cannot be used for the element.
    The document is non-conforming.</p>

    <p>Link types are associated with limited set of elements.
    They cannot be used with other elements.</p>

    <p>For example, link type <code>bookmark</code>
    can be used with <code>a</code> or <code>area</code> element,
    while it cannot be used with <code>link</code> element.</p>
  </d:desc>
</d:item>

<d:item name="invalid attribute value"
    class="attribute-value-error"
    modules="ContentChecker::XML ContentChecker::HTML ContentChecker::Atom">
  <d:message xml:lang="en">Attribute value <code><var>{@}</var></code>
  is not an allowed value.</d:message>
</d:item>

<d:item name="length:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not a length
  value.</d:message>
</d:item>

<d:item name="link type:non-conforming"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The link type <code><var>{value}</var></code>
  is non-conforming.</d:message>
  <d:desc xml:lang="en">
    <p>The specified link type is non-conforming, and therefore
    the document is non-conforming.</p>

    <dl class="switch">
    <dt>Link type <code>contents</code></dt>
      <dd>Use link type <code>index</code>.</dd>
    <dt>Link type <code>copyright</code></dt>
      <dd>Use link type <code>license</code>.</dd>
    <dt>Link type <code>home</code></dt>
      <dd>Use link type <code>index</code>.</dd>
    <dt>Link type <code>previous</code></dt>
      <dd>Use link type <code>prev</code>.</dd>
    <dt>Link type <code>start</code></dt>
      <dd>Use link type <code>first</code>.</dd>
    <dt>Link type <code>toc</code> or <code>top</code></dt>
      <dd>Use link type <code>index</code>.</dd>
    </dl>
  </d:desc>
</d:item>

<d:item name="meta content-type syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value is not a valid as a long
  character encoding declaration.</d:message>
</d:item>

<d:item name="mismatched charset name"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified character encoding name
  <code><var>{value}</var></code> is different from the actual document
  character encoding <code><var>{text}</var></code>.</d:message>
  <d:desc xml:lang="en">
    <p>The specified character encoding name is different from
    the character encoding of the document.  The document
    is non‐conforming.</p>
  </d:desc>
</d:item> 

<d:item name="mismatched charset name not checked"
    mopdules="ContentChecker::HTML">
  <d:message xml:lang="en">Whether the specified character encoding name
  <code><var>{value}</var></code> matches to the actual character encoding
  name cannot be checked since the input is not a byte stream.</d:message>
</d:item>

<d:item name="mode:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not a valid mode
  name.</d:message>
</d:item>

<d:item name="nninteger:out of range"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value is out of range.</d:message>
</d:item>

<d:item name="nninteger:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not a non‐negative
  integer.</d:message>
</d:item>

<d:item name="no referenced map"
    modules="ContentChecker">
  <d:message xml:lang="en">The <code>usemap</code> attribute references
  no image map.</d:message>
</d:item>

<d:item name="no referenced menu"
    modules="ContentChecker">
  <d:message xml:lang="en">The <code>contextmenu</code> attribute references
  no menu.</d:message>
</d:item>

<d:item name="no referenced header cell"
    modules="ContentChecker">
  <d:message xml:lang="en">There is no table header cell whose <code>id</code>
  is <code><var>{value}</var></code> in the same table.</d:message>
</d:item>

<d:item name="refresh:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">the specified value is not a valid as part
  of a <code>Refresh</code> pragma.</d:message>
</d:item>

<d:item name="repeat:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The attribute value is not an integer or 
  a string <code>template</code>.</d:message>
</d:item>

<d:item name="reserved browsing context name"
    class="attribute-value-error">
  <d:message xml:lang="en">Browsing context name 
  <code><var>{@}</var></code> is reserved.</d:message>
  <d:desc xml:lang="en">
    <p>The specified browsing context name is reserved.
    The document is non-conforming.</p>

    <p>Names of browsing contexts starting with <code>_</code>
    (<code>U+005F</code> <code class="charname">LOW LINE</code>)
    are reserved so that it must not be used.</p>

    <p>Old version of HTML, non-HTML markup languages, and
    Web browsers define or implements special reserved
    browsing context names <code>_blank</code>,
    <code>_main</code>, and <code>_replace</code>.
    However, they are <em>not</em> conforming attribute values.</p>
  </d:desc>
</d:item>

<d:item name="Reserved Prefixes and Namespace Names:Name"
    modules="ContentChecker::XML">
  <d:message xml:lang="en">Namespace name <code><var>{text}</var></code>
  is reserved and cannot be used for an arbitrary prefix.</d:message>
</d:item>

<d:item name="Reserved Prefixes and Namespace Names:Prefix"
    modules="ContentChecker::XML">
  <d:message xml:lang="en">Namespace prefix <code><var>{text}</var></code>
  is reserved and cannot be used for an arbitrary namespace name.</d:message>
</d:item>

<d:item name="link type:proposed"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Link type <code><var>{value}</var></code>
  is proposed but not accepted yet; it <em>should not</em> be
  used until it has been accepted.</d:message>
  <d:desc>
    <p>The link type is in the <i>proposed</i> status; it
    <em>should not</em> be used until it has been
    accepted.</p>

    <p><strong>Warning</strong>: The data served to the
    conforming checker might be out of date; it might have already
    been accepted or rejected.  The document might or might not be
    conforming depending on the status.  See WHATWG Wiki
    for the latest information.</p>
  </d:desc>
</d:item>

<d:item name="sizes:syntax error"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The specified value <code><var>{value}</var></code>
  is not a valid value.</d:message>
</d:item>

<d:item name="space in ID"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">White space characters are not allowed
  in the <code>id</code> attribute.</d:message>
</d:item>

<d:item name="template:not template"
    modules="ContentChecker ContentChecker::HTML">
  <d:message xml:lang="en">The node referenced by the <code>template</code>
  attribute is not a template.</d:message>
</d:item>

<d:item name="window name:empty"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Browsing context name must not be empty.</d:message>
</d:item>

<d:item name="window name:reserved"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">Browsing context name
  <code><var>{value}</var></code> is reserved.</d:message>
</d:item>

<d:item name="word not allowed"
    modules="ContentChecker::HTML">
  <d:message xml:lang="en">The word <code><var>{value}</var></code> is not
  allowed in this attribute.</d:message>
</d:item>

<d:item name="XML 1.0 NCName:syntax error"
    modules="RDFXML">
  <d:message xml:lang="en">The specified value is not a legal XML Namespaces
  1.0 <code>NCName</code>.</d:message>
</d:item>

<d:item name="xml:lang ne lang"
    modules="ContentChecker::XML ContentChecker::HTML">
  <d:message xml:lang="en">The value of the <code>xml:lang</code> attribute
  is different from the value of the <code>lang</code> attribute.</d:message>
  <d:message xml:lang="ja"><code>xml:lang</code> 属性の値が <code>lang</code>
  属性の値と異なります。</d:message>
  <d:desc xml:lang="en">
    <p>The value of the <code>xml:lang</code> attribute (either the
    <code>lang</code> attribute in the <code>xml</code> (i.e.
    <code>http://www.w3.org/XML/1998/namespace</code>) namespace, or
    the <code>xml:lang</code> attribute in no namespace) for the element has
    different value than that of the <code>lang</code> attribute in no
    namespace.</p>

    <p>For historical reason, there are two attributes applicable to HTML
    elements to specify language information of an element: <code>lang</code>
    and <code>xml:lang</code>.  In HTML documents, only <code>lang</code>
    attribute in no namespace is allowed and take effect; the
    <code>xml:lang</code> attribute in no namespace is ignored in HTML
    documents.  In XHTML documents, both <code>lang</code> and
    <code>xml:lang</code> attributes are allowed.</p>

    <p>In general, <em>only the <code>lang</code> attribute</em> need to be
    specified for an element.</p>

    <p>If both <code>lang</code> and <code>xml:lang</code> attributes are
    specified on the same element, their values must be the same value.</p>
  </d:desc>
  <d:desc xml:lang="ja">
    <p><code>xml:lang</code> 属性 (<code>xml</code> (=
    <code>http://www.w3.org/XML/1998/namespace</code>) 名前空間の
    <code>lang</code> 属性や名前空間に属さない 
    <code>xml:lang</code> 属性) の値が同じ要素の名前空間に属さない
    <code>lang</code> 属性の値と異なっています。</p>

    <p>歴史的な理由により、 HTML 要素の言語指定のための属性は 
    <code>lang</code> と <code>xml:lang</code> の2つがあります。 HTML
    文書では名前空間に属さない <code>lang</code> 属性だけが認められており、
    かつ効力があります。名前空間に属さない
    <code>xml:lang</code> 属性は HTML 文書では無視されます。 XHTML 文書では
    <code>lang</code> 属性も <code>xml:lang</code> 属性も認められています。</p>

    <p>通常、要素の言語情報は <em><code>lang</code> 
    属性だけ</em>を使って指定すれば十分です。</p>

    <p><code>lang</code> 属性と <code>xml:lang</code> 
    属性の両方を同じ要素に指定する場合、
    両者の値は同じでなければなりません。</p>
  </d:desc>
</d:item>

</section>

<section id="table-model-errors">
<h2>Table Model Errors</h2>

<d:item name="cell overlapping"
    modules="HTML::Table">
  <d:message xml:lang="en">Cell slot (<var>{text}</var>) is filled by
  multiple cells.</d:message>
</d:item>

<d:item name="colspan creates column with no anchored cell"
    modules="HTML::Table">
  <d:message xml:lang="en">This <code>colspan</code> attribute
  results in creating a table column that does not contain
  any cell anchored to it.</d:message>
</d:item>

<d:item name="column with no anchored cell"
    modules="HTML::Table">
  <d:message xml:lang="en">This column has no anchored cell.</d:message>
</d:item>

<d:item name="table:no cell in last row"
    class="table-model-error">
  <d:message xml:lang="en">The table has no cell (<code>td</code> or
  <code>th</code>) in the last row.</d:message>
</d:item>

<d:item name="table:rowspan extends table"
    class="table-model-error">
  <d:message xml:lang="en">This <code>rowspan</code> attribute
  results in creating a table row that does not contain
  any cell anchored to it.</d:message>
  <d:desc xml:lang="en">
    <p>The <code>rowspan</code> attribute value of the cell
    is so specified that it extends a table in the row axis.
    However, the extended row does not contain any cell by itself.
    The document is non-conforming.</p>

    <p>For example, the table below is non-conforming:
      <pre class="html bad example"><code>&lt;table>
&lt;tbody>
&lt;tr>&lt;td rowspan=2>&lt;/td>&lt;/tr>
&lt;/tbody>
&lt;/table></code></pre>
    ... since the second row contains only
    a cell that spans between first and second rows.</p>
  </d:desc>
</d:item>

<d:item name="row with no anchored cell"
    modules="HTML::Table">
  <d:message xml:lang="en">This row has no anchored cell.</d:message>