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<div class="header">
<h1>manakai's <abbr>XML</abbr> Conformance Checking</h1>
<h2>Working Draft <time datetime=2008-03-29>29 March 2008</time></h2>

<dl class="versions-uri">
<dt>This Version</dt>
  <dd><code class="URI">&lt;<a href="http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc-work"
      >http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc-work</a>&gt;</code></dd>
<dt>Latest Version</dt>
  <dd><code class="URI">&lt;<a href="http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc"
      >http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc</a>&gt;</code></dd>
<dt>Latest Working Draft</dt>
  <dd><code class="URI">&lt;<a href="http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc-work"
      >http://suika.fam.cx/www/markup/xml/xmlcc/xmlcc-work</a>&gt;</code></dd>
<!-- <dt>Previous Version</dt> -->
<dt>Version History</dt>
  <dd><code class=URI>&lt;<a href="http://suika.fam.cx/gate/cvs/markup/xml/xmlcc/xmlcc-work.en.html">http://suika.fam.cx/gate/cvs/markup/xml/xmlcc/xmlcc-work.en.html</a>&gt;</code></dd>
</dl>
<dl class="authors" id="author">
<dt>Author</dt>
  <dd><a href="http://suika.fam.cx/~wakaba/who?" rel="author"
      lang=ja>Wakaba</a>
  <code class="mail">&lt;<a href="mailto:w@suika.fam.cx" rel="author"
      >w@suika.fam.cx</a>&gt;</code></dd>
</dl>

<p class="copyright" lang="en">&#xA9; <time>2007</time>$B!>(B<time>2008</time> <a
    href="http://suika.fam.cx/~wakaba/who?" rel="author">Wakaba</a>.
Permission is granted to copy, distribute and/or modify this document
under the terms of the <a rel="license"
href="http://www.gnu.org/copyleft/fdl.html">GNU Free Documentation License</a>,
Version 1.2
or any later version published by the <a
href="http://www.fsf.org/">Free Software Foundation</a>;
with no Invariant Sections, no Front$B!>(BCover Texts, and no Back$B!>(BCover
Texts.  A copy of the license is
available at <code class="URI">&lt;<a
    href="http://www.gnu.org/copyleft/fdl.html"
    rel="license">http://www.gnu.org/copyleft/fdl.html</a>&gt;</code>.</p>
</div>

<div id="abstract" class="section">
<h2>Abstract</h2>

<div class="ed issue">...</div>

</div>

<div id="status" class="section">
<h2>Status of This Document</h2>

<p class=section-info><em>This section describes the status of this document
at the time of its publication.  Other documents
might supersede this document.</em></p>

<p>This document is a working draft, produced as part of the 
<a href="http://suika.fam.cx/www/markup/html/whatpm/readme">Whatpm</a>
subproject of the 
<a href="http://suika.fam.cx/www/manakai-core/doc/web/">manakai</a> 
project.  It might be updated, replaced, or obsoleted by
other documents at any time.  It is inappropriate to
cite this document as other than <q>work in progress</q>.</p>

<p>Comments on this document are welcome and
may be sent to the <a href="#author">author</a>.</p>

<p>Translations of thie document might be available.
The English version of the document is the only
normative version.</p>
</div>

<div id="introduction" class="section">
<h2>Introduction</h2>

<p class=section-info>This section is <em>non$B!>(Bnormative</em>.</p>

<div class="issue ed">...</div>


</div>

<div class="section" id="terminology">
<h2>Terminology</h2>

<p>The key words <q><em class="rfc2119">MUST</em></q>,
<q><em class="rfc2119">MUST NOT</em></q>,
<q><em class="rfc2119">SHOULD</em></q>,
<q><em class="rfc2119">SHOULD NOT</em></q>, and
<q><em class=rfc2119>MAY</em></q> in this
document are to be interpreted as described in 
<a href="urn:ietf:rfc:2119"><abbr title="Request for Comments">RFC</abbr> 
2119</a>
<cite class="bibref normative">[<a href="#ref-KEYWORDS">KEYWORDS</a>]</cite>.</p>

<!-- Strictly speaking the paragraph below is not part of terminology. -->
<p>All examples and notes in this specification are non$B!>(Bnormative,
as are all sections explicitly marked non$B!>(Bnormative.  Everything
else in this specification is normative.</p>

<p><span class=ed>Algorithm is normative but non-normative</span>.
In addition, the order in which <a href="#errors">errors</a> are
raised is undefined.</p>

<p>This document sometimes cites parts of <abbr>XML</abbr> 1.0 specification
by hyperlinks.  When the document being processed is an <abbr>XML</abbr> 1.1
document, however, corresponding parts of the <abbr>XML</abbr> 1.1 
specification should be consulted instead.</p>
</div>


<div class=section id=error-categories>
<h2>Error Classification</h2>

<p class=ed>If a <code>Document</code> node has no 
xml-well-formedness-error, entity-error, and unknown-error,
then it is well-formed.  If a well-formed <code>Document</code>
node has no xml-validity-error, it is valid.</p>

<div class="note memo">
<p>A well$B!>(Bformed <code>Document</code> can be safely serialized
into a well$B!>(Bformed XML document.  A valid <code>Document</code>
can be easily serialized into a valid XML document.</p>
</div>

<p class=ed>To be a conforming <a href="http://www.w3.org/TR/2006/REC-xml-20060816/#dt-validating">validating XML processor</a>,
...</p>

<p>Errors are classified into these 
<dfn id=error-category title="error category">error categories</dfn>:</p>

<dl id=errors>
<dt><dfn id=entity-error><code>entity-error</code></dfn></dt>
  <dd>
    <p class=ed>@@</p>
    <div class="note memo">
      <p>This <span class=ed>algorithm</span> does not support
      <abbr>DOM</abbr> tree with one or more <code>EntityReference</code>
      nodes.  It is expected that any entity references are expanded
      at the parse time and any unexpandable entity references
      make parse time errors raised so that never result in
      <abbr>DOM</abbr> tree with <code>EntityReference</code> nodes.</p>
    </div>
  </dd>
<dt><dfn id=round-trip-error><code>round-trip-error</code></dfn></dt>
  <dd class=ed>@@</dd>
<dt><dfn id=round-trip-warning><code>round-trip-warning</code></dfn></dt>
  <dd>
    <p>A <a href="#round-trip-warning"><code>round-trip-warning</code></a>
    will be raised when a construct, which might not be restored to the same
    construct when it is serialized and then re-parsed by a conforming
    processor, is encountered.</p>
    <div class="example memo">
      <p>For a <code>Comment</code> node a
      <a href="#round-trip-warning"><code>round-trip-warning</code></a> will
      be raised, since <abbr>XML</abbr> processors are not required to
      report texts of comments for applications.</p>
    </div>
  </dd>
<dt class=ed><dfn id=unknown-error><code>unknown-error</code></dfn>?</dt>
  <dd class=ed>@@</dd>
<dt><dfn id=xml-misc-error><code>xml-misc-error</code></dt>
  <dd>An <abbr>XML</abbr> <i>error</i> (<abbr>XML</abbr> 1.0
  <cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite> 
  <a href="http://www.w3.org/TR/2006/REC-xml-20060816/#dt-error">error</a> /
  <abbr>XML</abbr> 1.1
  <cite class="bibref normative">[<a href="#ref-XML11">XML11</a>]</cite>
  <a href="@@/#dt-error">error</a>)
  that is not classified to any other <a href="#error-category">error
  category</a>.</dd>
<dt><dfn id=xml-misc-fatal-error><code>xml-misc-fatal-error</code></dt>
  <dd>An <abbr>XML</abbr> <i>fatal error</i> (<abbr>XML</abbr> 1.0
  <cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite> 
  <a href="http://www.w3.org/TR/2006/REC-xml-20060816/#dt-fatal">fatal
  error</a> / <abbr>XML</abbr> 1.1
  <cite class="bibref normative">[<a href="#ref-XML11">XML11</a>]</cite>
  <a href="@@/#dt-fatal">fatal error</a>)
  that is not classified to any other <a href="#error-category">error
  category</a>. <span class=ed>@@ What errors fall into this category?</span></dd>
<dt><dfn id=xml-misc-recommendation><code>xml-misc-recommendation</code></dfn></dt>
  <dd>
    <p>An
    <a href="#xml-misc-recommendation"><code>xml-misc-recommendation</code></a>
    will be raised if a <em class=rfc2119>SHOULD</em>$B!>(Blevel requirement
    in <abbr>XML</abbr> specification is not met.</p>
  </dd>
<dt><dfn id=xml-validity-error><code>xml-validity-error</code></dfn></dt>
  <dd>A violation of validity constraint in XML document.</dd>
<dt><dfn id=xml-well-formedness-error><code>xml-well-formedness-error</code></dfn></dt>
  <dd><p>If an <code>xml-well-formedness-error</code> is raised,
  it would not be possible to generate an XML serialization that
  would match to the appropriate production rule and that would not 
  violate to any well$B!>(Bformedness constraint in XML
  specification <cite class="bibref normative">[<a href="#ref-XML10">XML10</a>,
  <a href="#ref-XML11">XML11</a>]</cite>.</p></dd>
</dl>

<div class=ed><p>@@ TODO: #dt-atuseroption at user option
(MAY or MUST), #dt-compat for compatibility,
#dt-interop for interoperability</p>

<p>TODO: XML 1.1, XML Namespace 1.0/1.1, xml:base, xml:id
</div>

</div>

<div class=section id=parsing-xml>
<h2>Parsing <abbr>XML</abbr> Document</h2>

<p>When an <abbr>XML</abbr> document is parsed, the following clauses
are applied:</p>
<dl>
<dt>For each document
  <dd>If the <abbr>XML</abbr> document does not begin with an
  <abbr>XML</abbr> declaration, then the parser <em class=rfc2119>MUST</em>
  raise an
  <a href="#xml-misc-recommentation" id=xmr-xml-decl><code>xml-misc-recommendation</code></a>.
<dt>For each internal general entity declaration processed by the parser
  <dd>If the 
  <a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NT-EntityValue"><code>EntityValue</code></a>
  part of the general entity declaration contains a bare <code>U+003C</code>
  <code>LESS-THAN SIGN</code> (<code>&lt;</code>) character, then the parser
  <em class=rfc2119>MUST</em> raise an
  <a href="#xml-misc-warning" id=xmw-entity-value-lt><code>xml-misc-warning</code></a>.<!--
"strongly advised to avoid" in a Note in Section 2.3 of [XML10], [XML11].
-->
<dt>For each element type declaration processed by the parser
  <dd>If there is another element type declaration whose <code>Name</code>
  is equal to the <code>Name</code> of the element type declaration, then
  the parser <em class=rfc2119>MUST</em> raise an 
  <a href="#xml-validity-error" id=vc-edunique><code>xml-validity-error</code></a>.
<!--
  NOTE: <!ATTLIST a xml:space (default) #IMPLIED xml:space CDATA #IMPLIED>
  will not be warned.
-->
<dt>For each empty-element tag
  <dd>If the <code>Name</code> of the tag is not declared by a processed
  element type declaration as <code>EMPTY</code> content, then the parser
  <em class=rfc2119>MUST</em> raise an
  <a href="#xml-misc-recommentation" id=xmr-emptyelemtag-not-empty><code>xml-misc-recommendation</code></a>.
<dt>For each start-tag
  <dd>If the <code>Name</code> of the tag is declared by a processed element
  type declaration as <code>EMPTY</code> content, then the parser
  <em class=rfc2119>MUST</em> raise an
  <a href="#xml-misc-recommentation" id=xmr-empty-not-emptyelemtag><code>xml-misc-recommendation</code></a>.
</dl>

<p>In addition, the parser <em class=rfc2119>MUST</em> check whether the
following constraints are met.

<p><strong>Well-formedness constraints</strong>.  For each violation to
one of constraints below, an
<a href="#xml-well-formedness-error"><code>xml-well-formedness-error</code></a>
<em class=rfc2119>MUST</em> be raised.  The list of well-formedness
constraints is below:
<ul>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#wfc-PEinInternalSubset">Well-formedness constraint: PEs in Internal Subset</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#ExtSubset">Well-formedness constraint: External Subset</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#PE-between-Decls">Well-formedness constraint: PE Between Declarations</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#GIMatch">Well-formedness constraint: Element Type Match</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#uniqattspec">Well-formedness constraint: Unique Att Spec</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NoExternalRefs">Well-formedness constraint: No External Entity References</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#CleanAttrVals">Well-formedness constraint: No &lt; in Attribute Values</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#wf-Legalchar">Well-formedness constraint: Legal Character</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#textent">Well-formedness constraint: Parsed Entity</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#norecursion">Well-formedness constraint: No Recursion</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#indtd">Well-formedness constraint: In DTD</a>
</ul>

<p><strong>Validity constraints</strong>.  For each violation to
one of constraints below, an
<a href="#xml-validity-error"><code>xml-validity-error</code></a>.
<em class=rfc2119>MUST</em> be raised.  The list of validity
constraints is below:
<ul>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#vc-PEinMarkupDecl">Validity constraint: Proper Declaration/PE Nesting</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#vc-PEinGroup">Validity constraint: Proper Group/PE Nesting</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#condsec-nesting">Validity constraint: Proper Conditional Section/PE Nesting</a>
<li><a href="http://www.w3.org/TR/2006/REC-xml-20060816/#UniqueNotationName">Validity constraint: Unique Notation Name</a>
</ul>

<p><strong>Other creteria</strong>.  For each violation to
one of constraints below, an
<a href="#xml-misc-recommendation"><code>xml-misc-recommendation</code></a>
<em class=rfc2119>MUST</em> be raised.  The list of constraints is below:
<ul>
<li><q>For interoperability, if a parameter-entity reference appears in a 
<code>choice</code>, <code>seq</code>, or <code>Mixed</code> construct, its 
replacement text <em class=rfc2119>SHOULD</em> contain at least one non-blank 
character, and neither the first nor last non-blank character of the 
replacement text <em class=rfc2119>SHOULD</em> be a connector (<code>|</code> 
or <code>,</code>).</q>
<li><q>External parsed entities <em class=rfc2119>SHOULD</em> each begin with a
text declaration.</q>
</ul>

<!--
<li><q>For interoperability, an XML processor <em class=rfc2119>MAY</em> at user option issue a warning when more than one attribute-list declaration is provided for a given element type, or more than one attribute definition is provided for a given attribute, but this is not an error.</q>

<a href="#xml-misc-error" id=xme-attr-xml-space><code>xml-misc-error</code></a>.
<li>It is an error for a reference to an unparsed entity to appear in the EntityValue in an entity declaration."
-->

<!--


@@ Need detailed review, but maybe should be in parsing phase

#vc-check-rmd Validity constraint: Standalone Document Declaration

@@ Need dtailed review

#wf-entdeclared Well-formedness constraint: Entity Declared
#vc-entdeclared Validity constraint: Entity Declared
"For interoperability, valid documents SHOULD declare the entities amp, lt, gt, apos, quot, in the form specified in 4.6 Predefined Entities."
"If the entities lt or amp are declared, they MUST be declared as internal entities whose replacement text is a character reference to the respective character (less-than sign or ampersand) being escaped; the double escaping is REQUIRED for these entities so that references to them produce a well-formed result. If the entities gt, apos, or quot are declared, they MUST be declared as internal entities whose replacement text is the single character being escaped (or a character reference to that character; the double escaping here is OPTIONAL but harmless)."

@@ flaged and then reported in DOM check phase

"Entities encoded in UTF-16 MUST and entities encoded in UTF-8 MAY begin with the Byte Order Mark"
"In the absence of external character encoding information (such as MIME headers), parsed entities which are stored in an encoding other than UTF-8 or UTF-16 MUST begin with a text declaration"
"In an encoding declaration, the values "UTF-8", "UTF-16", "ISO-10646-UCS-2", and "ISO-10646-UCS-4" SHOULD be used for the various encodings and transformations of Unicode / ISO/IEC 10646, the values "ISO-8859-1", "ISO-8859-2", ... "ISO-8859-n" (where n is the part number) SHOULD be used for the parts of ISO 8859, and the values "ISO-2022-JP", "Shift_JIS", and "EUC-JP" SHOULD be used for the various encoded forms of JIS X-0208-1997. It is RECOMMENDED that character encodings registered (as charsets) with the Internet Assigned Numbers Authority [IANA-CHARSETS], other than those just listed, be referred to using their registered names; other encodings SHOULD use names starting with an "x-" prefix."

@@ in parsing phase

"It is a fatal error when an XML processor encounters an entity with an encoding that it is unable to process. It is a fatal error if an XML entity is determined (via default, encoding declaration, or higher-level protocol) to be in a certain encoding but contains byte sequences that are not legal in that encoding."

@@ We should phrase out what the parser should do where the XML specification
left undefined.  For example: Comment must be converted to a Comment node,
illegal xml:space value must be preserved, so on.

-->
</div>

<div class="section" id=checking-dom>
<h2>Checking <abbr>DOM</abbr></h2>

<p>The following algorithms and definitions are applied to
<abbr>XML</abbr> documents; especially, they are not applied
to <abbr>HTML</abbr> documents.<!-- TODO: ref to HTML5 --></p>

<div class=section id=definitions>
<h3>Definitions</h3>

<p>The <dfn id=xml-version><abbr>XML</abbr> version</dfn> of a node is 
the <abbr>XML</abbr> version of the document to which the node belongs.
For a <code>Documemt</code> node, the <abbr>XML</abbr> version
of the document is the value of the <code>xmlVersion</code>
attribute of the node.  For a <code>DocumentType</code> node whose 
<code>ownerDocument</code> attribute is set to <code>null</code>,
the <abbr>XML</abbr> version of the document is <code>1.0</code><!--
since createDocumentType [DOM3CORE] assumes XML 1.0 [XML10TE] -->.
For any other node, the <abbr>XML</abbr> version of the document
is that of the <code>Document</code> node contained in the
<code>ownerDocument</code> attribute of the node.</p>

</div>


<div class=section id=checking-components>
<h3>Conformance Checking Algorithms for Components</h3>

<p>To
<dfn id=algorithm-to-validate-an-xml-character-data title="validate an XML string">to
validate an <abbr>XML</abbr> string (<dfn id=var-s><var>s</var></dfn>)</dfn>,
the following algorithm <em class=rfc2119>MUST</em> be used:</p>
<ol>
<li>If <var>s</var> contains a character that is <em>not</em> in
the character class <a href="#class-Char10"><code>Char10</code></a>, 
then raise an
<a href="#xml-well-formedness-error" id=wfe-illegal-char><code>xml-well-formedness-error</code></a>.</li>
<li>If <var>s</var> contains a character that is in the character
class <a href="#class-CompatChar10"><code>CompatChar10</code></a>,
then raise an
<a href="#xml-misc-warning" id=xmw-compat-char><code>xml-misc-warning</code></a>.</li>
<li>If <var>s</var> contains a character that is in the character
class <a href="#class-ControlChar10"><code>ControlChar10</code></a>,
then raise an
<a href="#xml-misc-warning" id=xmw-control-char><code>xml-misc-warning</code></a>.</li>
<li class=ed>@@ XML 1.1 support</li>
<li>If <var>s</var> contains a <code class=char>U+000D</code>
<code class=charname>CARRIAGE RETURN</code> character, then
raise a 
<a href="#round-trip-error" id=rte-cr><code>round-trip-error</code></a>.
<span class=ed>@@ We should not raise duplicate errors for U+000D
in attribute values.  In addition, we should support a mode where
U+000D will be serialized as &#x000D; (so that no round-trip-error
will be raised).</span></li>
</ol>

<p>To
<dfn id=algorithm-to-validate-a-name title="validate a Name">validate a
<code>Name</code> (<dfn id=var-name-s><var>s</var></dfn>)</dfn>, the following
algorithm <em class=rfc2119>MUST</em> be used:</p>
<ol>
<li>If <var>s</var> is an empty string, then raise an
<a href="#xml-well-formedness-error" id=wfe-name-empty><code>xml-well-formedness-error</code></a>.
Abort these steps.</li>
<li><a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">Validate
<var>s</var> as an <abbr>XML</abbr> string</a>.</li>
<li>If the first character in <var>s</var> is a character that is 
<em>not</em> in the character class 
<a href="#class-NameStartChar10"><code>NameStartChar10</code></a>, then raise
an
<a href="#xml-well-formedness-error" id=wfe-name-startchar><code>xml-well-formedness-error</code></a>.</li>
<li>If a character other than the first character in <var>s</var> is a 
character that is <em>not</em> in the character class 
<a href="#class-NameChar10"><code>NameChar10</code></a>, then raise an
<a href="#xml-well-formedness-error" id=wfe-name-char><code>xml-well-formedness-error</code></a>.</li>
<li>If <var>s</var> begins with the string <code>xml</code> (in any
case combination), then raise an
<a href="#xml-misc-warning" id=xmw-reserved-name><code>xml-misc-warning</code></a>.
<span class=ed>@@ except for attribute names <code>xml:lang</code>,
<code>xml:space</code>, <code>xml:base</code>, <code>xml:id</code>,
<code>xmlns</code>, <code>xmlns:<var>*</var></code>,
pi name <code>xml-stylesheet</code>.</span><!--
"names beginning with a match to (('X'|'x')('M'|'m')('L'|'l')) are reserved for standardization in this or future versions of this specification.":
xmlns, xml-stylesheet, xml:base and xml:id specifications violate to this sentense!
--></li>
<!-- COLON in Name is a lowercase "should not" in a Note of [XML10],
[XML11]. -->
<li class=ed>@@ XML 1.1 support</li>
</ol>

<p>To
<dfn id=algorithm-to-validate-an-ncname title="validate an NCName">validate
an <code>NCName</code> (<dfn id=var-ncname-s><var>s</var></dfn>)</dfn>, the
following algorithm <em class=rfc2119>MUST</em> be used:</p>
<ol>
<li><a href="#algorithm-to-validate-a-name" title="validate a Name">Validate
<var>s</var> as a <code>Name</code></a>.</li>
<li class=ed>@@</li>
</ol>

<p>To 
<dfn id=algorithm-to-validate-a-public-identifier title="validate a public identifier">validate
a public identifier (<dfn id=var-pid><var>pid</var></dfn>)</dfn>, the
following algorithm <em class=rfc2119>MUST</em> be used:</p>
<ol>
<li>If <var>pid</var> is <code>null</code>, abort these steps.</li>
<li>If <var>pid</var> contains a character that is <em>not</em> in the
character class <a href="#class-PubidChar"><code>PubidChar</code></a>, then
raise an
<a href="#xml-well-formedness-error" id=wfe-pubid-char><code>xml-well-formedness-error</code></a>.</li>
  <li>If <var>pid</var> contains one of <code class=char>U+0009</code>
  <code class=charname>CHARACTER TABULATION</code>, 
  <code class=char>U+000A</code> <code class=charname>CARRIAGE RETURN</code>,
  and <code class=char>U+000D</code> <code class=charname>LINE FEED</code>
  characters, if the first character of <var>pid</var> is
  <code class=char>U+0020</code> <code class=charname>SPACE</code> character,
  if the last character of <var>pid</var> is <code class=char>U+0020</code>
  <code class=charname>SPACE</code> character, or if there is a
  <code class=char>U+0020</code> <code class=charname>SPACE</code> character
  immediately followed by another <code class=char>U+0020</code>
  <code class=charname>SPACE</code> character in <var>pid</var>, then it is a
  <a href="#round-trip-error" id=rte-pubid-space><code>round-trip-error</code></a>.
  <span class=ed>Is this really a roundtripness problem?  XML spec
  does only define the way to match public identifiers in fact, no
  canonical form.</span></li>
</ol>

<p>To 
<dfn id=algorithm-to-validate-a-system-identifier title="validate a system identifier">validate
a system identifier (<dfn id=var-sid><var>sid</var></dfn>)</dfn>, the
following algorithm <em class=rfc2119>MUST</em> be used:</p>
<ol>
  <li>If <var>sid</var> is <code>null</code>, abort these steps.</li>
<li><a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">Validate
<var>sid</var> as an <abbr>XML</abbr> string</a>.</li>
  <li>If <var>sid</var> contains both <code class=char>U+0022</code>
  <code class=charname>QUOTATION MARK</code> (<code class=char>"</code>) and
  <code class=char>U+0027</code> <code class=charname>APOSTROPHE</code>
  (<code class=char>'</code>) characters, raise an
  <a href="#xml-well-formedness-error" id=wfe-sid-lit><code>xml-well-formedness-error</code></a>.</li>
  <li>If <var>sid</var> contains at least one <code class=char>U+0023</code>
  <code class=charname>NUMBER SIGN</code> (<code class=char>#</code>)
  character, then raise an
  <a href="#xml-misc-error" id=xme-sid-fragment><code>xml-misc-error</code></a>.</li>
  <li class=ed>@@ If <var>sid</var> cannot be converted to a URI
  reference, then raise a fact-level error (xml-misc-warning?).<!--
  XML 1.0 has no conformance language for system identifier being
  a URI reference. --></li>
</ol>

</div>

<div class=section id=checking-node>
<h3>Checking <code>Node</code></h3>

<p>The algorithm <dfn title="to check a node" id=algorithm-to-check-a-node>to 
check a node (<dfn id=var-n><var>n</var></dfn>)</dfn> is defined as 
following:</p>
<dl class=switch>
<dt>If <var>n</var> is an <code>Attr</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>localName</code> attribute value as an <code>NCName</code></a>.</li>
    <li>If the <code>prefix</code> attribute value is different from
    <code>null</code>, then <a href="#algorithm-to-validate-an-ncname">validate
    the <code>prefix</code> attribute value as an <code>NCName</code></a>.</li>
    <li>For each node <dfn id=var-attr-nc><var>n<sub><var>c</var></sub></var></dfn> in the
    <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> a
      <code>Text</code> or <code>EntityReference</code> node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-attr-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is an
      <code>EntityReference</code> node, then it is an 
      <a href="#entity-error" id=ee-attr-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recusrively.</li>
      </ol></li>
    <li>If <code>nodeName</code> attribute of <var>n</var> is
    <code>xml:space</code> <span class=ed>@@ or {xml namespace}:space ?</span>
    and <code>value</code> attribute of <var>n</var> is neither 
    <code>default</code> nor <code>preserve</code>, then it is an
    <a href="#xml-misc-error" id=xme-attr-xml-space><code>xml-misc-error</code></a>.<!--
    Note that <!ATTLIST e xml:space (default|preserve) "a">...
    <e xml:space="default"/> is conforming and valid. --></li>
    <li class=ed>@@ xml:lang value is not a language tag [RFC 3066 or its
    successor] or an empty string, then xml-misc-warning
    (a "fact"-level error; not an XML error).</li>
    <li class=ed>@@ <code>specified</code>,
    <code>manakaiAttributeType</code> (#ValueType Validity constraint: Attribute Value Type)</li>
    <!-- xml:space MUST be declared to be valid. -->
    <li>Let <dfn id=var-v><var>v</var></dfn> be the value of the
    attribute <code>value</code> of <var>n</var>.</li>
    <li>Validate the <var>n</var> against the <span class=ed>declared 
    type</span> as following:
      <dl class=switch>
      <dt class=ed><code>ID_ATTR</code></dt>
        <dd>
          <ol>
          <li><span class=ed>Validate <var>v</var> as an
          <code>Name</code>.</span>  If it fails, then raise an
          <a href="#xml-validity-error" id=vc-id-name><code>xml-validity-error</code></a>.</li>
          <li><span class=ed>If <code>ID</code> <var>v</var> is defined,</span>
          then raise an  
          <a href="#xml-validity-error" id=vc-id-duplication><code>xml-validity-error</code></a>.</li>
          </ol>
        </dd>
      <dt class=ed>IDREF_ATTR</dt>
        <dd>
          <ol>
          <li><span class=ed>Validate <var>v</var> as an
          <code>Name</code>.</span>  If it fails, then raise an
          <a href="#xml-validity-error" id=vc-idref-name><code>xml-validity-error</code></a>.</li>
          <li><span class=ed>If <code>ID</code> <var>v</var> is NOT
          defined,</span> then raise an  
          <a href="#xml-validity-error" id=vc-idref-match><code>xml-validity-error</code></a>.</li>
          </ol>
        </dd>
      <dt class=ed>IDREFS_ATTR</dt>
        <dd class=ed>@@</dd>
      <dt class=ed>ENTITY_ATTR</dt>
        <dd>
          <ol>
          <li><span class=ed>Validate <var>v</var> as an
          <code>Name</code>.</span>  If it fails, then raise an
          <a href="#xml-validity-error" id=vc-entname-name><code>xml-validity-error</code></a>.</li>
          <li><span class=ed>If <code>Entity</code> <var>v</var> is NOT
          defined,</span> then raise an  
          <a href="#xml-validity-error" id=vc-entname-match><code>xml-validity-error</code></a>.</li>
          </ol>
        </dd>
      <dt class=ed>ENTITIES_ATTR</dt>
        <dd class=ed>@@</dd>
      <dt class=ed>NMTOKEN_ATTR</dt>
        <dd>
          <ol>
          <li><span class=ed>Validate <var>v</var> as an
          <code>Nmtoken</code>.</span>  If it fails, then raise an
          <a href="#xml-validity-error" id=vc-nmtok-name><code>xml-validity-error</code></a>.</li>
          </ol>
        </dd>
      <dt class=ed>NMTOKENS_ATTR</dt>
        <dd class=ed>@@</dd>
      <dt class=ed>NOTATION_ATTR</dt>
        <dd class=ed><var>v</var> must be one of enumerated values.
        If not, then raise an
        <a href="#xml-validity-error" id=vc-notatn-match><code>xml-validity-error</code></a>.</dd>
      <dt class=ed>ENUMERATED_ATTR</dt>
        <dd class=ed><var>v</var> must be one of enumerated values.
        If not, then raise an
        <a href="#xml-validity-error" id=vc-enum><code>xml-validity-error</code></a>.</dd>
      <dt class=ed>@@</dt>
      </dl>
    </li>
    <li>If <span class=ed>type ID and default is NOT #IMPLIED or #REQUIRED</span>, then
    raise an
    <a href="#xml-validity-error" id=vc-id-default><code>xml-validity-error</code></a>.</li>
    <li class=ed>@@ #FixedAttr Validity constraint: Fixed Attribute Default</li>
    <li class=ed>@@ strict serialization error for U+000D, U+000A, and
    U+0009 characters, leading/trailing U+0020, and U+0020{2,} string?</li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>AttributeDefinition</code> node</dt>
  <dd>
    <ol>
    <li class=ed></li>
    <li>If <code>nodeName</code> attribute of <var>n</var> is
    <code>xml:space</code> <span class=ed>@@ or {xml namespace}:space ?</span>
    and <span class=ed>its declared type is different from (default|preserve),
    (preserve|default), (default), or (preserve)</span>, then raise an
    <a href="#xml-misc-error" id=xme-at-xml-space><code>xml-misc-error</code></a>.</li>
    <li>For each node <dfn id=var-ad-nc><var>n<sub><var>c</var></sub></var></dfn> in the
    <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> a
      <code>Text</code> or <code>EntityReference</code> node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-at-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is an
      <code>EntityReference</code> node, then it is an 
      <a href="#entity-error" id=ee-at-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recusrively.</li>
      </ol></li>
    <li class=ed>If <code>NOTATION_ATTR</code>, enumerated values MUST
    be declared.  If not, then raise an
    <a href="#xml-validity-error" id=vc-notatn-declared><code>xml-validity-error</code></a>.</li>
    <li class=ed>If <code>NOTATION_ATTR</code> or <code>ENUMERATED_ATTR</code>,
    values MUST all be distinct.  If not, then raise an
    <a href="#xml-validity-error" id=vc-no-duplicate-tokens><code>xml-validity-error</code></a>.</li>
    <li class=ed>If <code>NOTATION_ATTR</code> on an <code>EMPTY</code> 
    element, then raise an
    <a href="#xml-validity-error" id=vc-no-notation-empty><code>xml-validity-error</code></a>.</li>
    <li class=ed>@@ #defattrvalid Validity constraint: Attribute Default Value Syntactically Correct</li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>CDATASection</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">Validate the 
    <code>data</code> attribute value as an <abbr>XML</abbr> character
    data</a>.</li>
    <li>If the <code>data</code> attribute value contains
    a string <code>]]></code>, then raise an
    <a href="#xml-well-formedness-error" id=wfe-cs-mse><code>xml-well-formedness-error</code></a>.<!-- "for compatibility" --></li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-cs-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>Comment</code> node</dt>
  <dd>
    <ol>
    <li>Raise an
    <a href="#round-trip-warning" id=rtw-comment><code>round-trip-warning</code></a>.</li>
    <li><a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">Validate the 
    <code>data</code> attribute value as an <abbr>XML</abbr> character
    data</a>.</li>
    <li>If the <code>data</code> attribute value contains
    a string <code>--</code>, or if it ends with a character
    <code>-</code>, then raise an
    <a href="#xml-well-formedness-error" id=wfe-comment-com><code>xml-well-formedness-error</code></a>.<!--
    "for compatibility" --></li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-comment-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>Document</code> node</dt>
  <dd>
    <ol>
    <li>If <a href="#xml-version"><abbr>XML</abbr> version</a> of <var>n</var>
    is different from <code>1.0</code> or <code>1.1</code>,
    then it is an <code class=ed>unknown-error?</code>.</li>
    <li>If the <code>xmlEncoding</code> attribute value does <em>not</em>
    match to <code>[A-Za-z] ([A-Za-z0-9._] | '-')*</code>
    <span class=ed>@@ formal def</span>, then it is an
    <a href="#xml-well-formedness-error" id=wfe-encoding><code>xml-well-formedness-error</code></a>.</li>
    <li>The <code>childNodes</code> list of <var>n</var> have to
    consist of zero or more <code>Comment</code> and/or
    <code>ProcessingInstruction</code> nodes, followed by
    an optional <code>DocumentType</code> node, followed
    by zero or more <code>Comment</code> and/or
    <code>ProcessingInstruction</code> nodes, followed by
    an <code>Element</code> node, followed
    by zero or more <code>Comment</code> and/or
    <code>ProcessingInstruction</code> nodes.  Any violation to this is an
    <a href="#xml-well-formedness-error" id=wfe-document-child><code>xml-well-formedness-error</code></a>.</li>
    <li>For each node <dfn id=var-document-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> an
      <code>EntityReference</code> node, then
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recursively.</li>
      </ol></li>
    <li class=ed>@@ <code>allDeclarationsProcessed</code></li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>DocumentFragment</code> node</dt>
  <dd>
    <ol>
    <li>For each node <dfn id=var-df-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> an
      <code>Element</code>, <code>Text</code>, <code>CDATASection</code>,
      <code>Comment</code>, <code>ProcessingInstruction</code>, or
      <code>EntityReference</code> node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-df-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is an
      <code>EntityReference</code> node, then it is an
      <a href="#entity-error" id=ee-df-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recursively.</li>
      </ol></li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>DocumentType</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>nodeName</code> attribute value as an <code>NCName</code></a>.</li>
    <li>Follow the following substeps:
      <ol>
      <li>If <code>ownerDocument</code> attribute of <var>n</var> is
      <code>null</code>, then abort these substeps.</li>
      <li>If <code>documentElement</code> attribute of the node
      set to <code>ownerDocument</code> attribute of <var>n</var> is
      <code>null</code>, then abort these substeps.</li>
      <li>If <code>nodeName</code> attribute of the node set to
      <code>documentElement</code> attribute of the node set to
      <code>ownerDocument</code> attribute of <var>n</var> is
      different from <code>nodeName</code> of <var>n</var>,
      then raise an
      <a href="#xml-validity-error" id=vc-roottype><code>xml-validity-error</code></a>.</li></li>
      </ol>
    </li>
    <li><a href="#algorithm-to-validate-a-public-identifier" title="validate a public identifier">Validate
    the <code>publicId</code> attribute value as a public identifier</a>.</li>
    <li><a href="#algorithm-to-validate-a-system-identifier" title="validate a system identifier">Validate
    the <code>systemId</code> attribute value as a system identifier</a>.</li>
    <li>If the <code>publicId</code> attribute value of <var>n</var> is
    <em>not</em> <code>null</code> and the <code>systemId</code> attribute
    value of <var>n</var> is <code>null</code>, then raise an
    <a href="#xml-well-formedness-error" id=wfe-dt-sid><code>xml-well-formedness-error</code></a>.
    <span class=ed>@@ publicId == null?  Or, publicId == ""</span></li>
    <li>For each node <dfn id=var-dt-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> a
      <code>ProcessingInstruction</code> node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-dt-child><code>xml-well-formedness-error</code></a>.
      <span class=ed>@@ ref to manakai's extensions</span></li>
      <li>Otherwise, <!-- if n_c is not an EntityReference node, -->
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recusrively.</li>
      </ol></li>
    <li>For each node in the <code>entities</code>, <code>notations</code>,
    and <code>elementTypes</code> lists of <var>n</var>,
    <a href="#algorithm-to-check-a-node" title="check a node">check the
    node</a> recursively.</li>
    <li class=ed>@@ externally declared?</li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>Element</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>localName</code> attribute value as an <code>NCName</code></a>.</li>
    <li>If the <code>prefix</code> attribute value is different from
    <code>null</code>, then <a href="#algorithm-to-validate-an-ncname">validate
    the <code>prefix</code> attribute value as an <code>NCName</code></a>.</li>
    <li>For each node <dfn id=var-element-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> an 
      <code>Element</code>,
      <code>Text</code>, <code>CDATASection</code>, <code>Comment</code>,
      <code>ProcessingInstruction</code>, or
      <code>EntityReference</code> node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-element-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is an
      <code>EntityReference</code> node, then it is an
      <a href="#entity-error" id=ee-element-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recursively.</li>
      </ol></li>
    <li class=ed>@@ #elementvalid Validity constraint: Element Valid</li>
    <li>Let <var>attrs</var> be the value of the <code>attribute</code>
    attribute of <var>n</var>.  Check conformance of <var>attrs</var>
    as following:
      <ol>
      <li>If <var>attrs</var> contains an <code>Attr</code> node whose
      <code>nodeName</code> attribute value is equal to that of another
      <code>Attr</code> node in <var>attrs</var>, then raise an
      <a href="#xml-well-formedness-error" id=wfe-uniqattspec><code>xml-well-formedness-error</code></a>.<!--
      #uniqattspec Well-formedness constraint: Unique Att Spec --></li>
      <li class=ed>@@ #RequiredAttr Validity constraint: Required Attribute</li>
      </ol>
    </li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>ElementTypeDefinition</code> node</dt>
  <dd>
    <ol>
    <li class=ed></li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-et-child><code>xml-well-formedness-error</code></a>.</li>
    <li class=ed>@@ <q cite="http://www.w3.org/TR/2006/REC-xml-20060816/#elemdecls">At user option, an XML processor MAY issue a warning when a declaration mentions an element type for which no declaration is provided, but this is not an error.</q></li>
    <li class=ed>@@ <q cite="http://www.w3.org/TR/2006/REC-xml-20060816/#sec-element-content">For compatibility, it is an error if the content model allows an element to match more than one occurrence of an element type in the content model. </q></li>
    <li class=ed>@@ #vc-MixedChildrenUnique
    Validity constraint: No Duplicate Types</li>
    <li class=ed>@@ <q cite="http://www.w3.org/TR/2006/REC-xml-20060816/#attdecls">At user option, an XML processor MAY issue a warning if attributes are declared for an element type not itself declared, but this is not an error.</q></li>
    <li>If there is more than one <code>AttributeDefinition</code> node
    with <span class=ed>attribute type <code>ID</code></span> in the 
    <code>NamedNodeMap</code> list contained in the 
    <code>attributeDefinitions</code> attribute of <var>n</var>, then raise an
    <a href="#xml-validity-error" id=vc-one-id-per-el><code>xml-validity-error</code></a>.</li>
    <li>If there is more than one <code>AttributeDefinition</code> node
    with <span class=ed>attribute type <code>NOTATION</code></span> in the 
    <code>NamedNodeMap</code> list contained in the 
    <code>attributeDefinitions</code> attribute of <var>n</var>, then raise an
    <a href="#xml-validity-error" id=vc-one-notation-per><code>xml-validity-error</code></a>.</li>
    <li class=ed>"For interoperability, the same Nmtoken  SHOULD NOT occur more than once in the enumerated attribute types of a single element type."</li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>Entity</code> node whose
<code>notationName</code> attribute value is <code>null</code> (i.e. a
parsed entity)</dt>
  <dd>
    <ol>
    <li>Raise an
    <a href="#entity-error" id=ee-entity-node><code>entity-error</code></a>.</li>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>nodeName</code> attribute value as an <code>NCName</code></a>.</li>
    <li><a href="#algorithm-to-validate-a-public-identifier" title="validate a public identifier">Validate
    the <code>publicId</code> attribute value as a public identifier</a>.</li>
    <li><a href="#algorithm-to-validate-a-system-identifier" title="validate a system identifier">Validate
    the <code>systemId</code> attribute value as a system identifier</a>.</li>
    <li>If the <code>publicId</code> attribute value of <var>n</var> is
    <em>not</em> <code>null</code> and the <code>systemId</code> attribute
    value of <var>n</var> is <code>null</code>, then raise an
    <a href="#xml-well-formedness-error" id=wfe-entity-sid><code>xml-well-formedness-error</code></a>.</li>
    <li>For each node <dfn id=var-entity-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> an
      <code>Element</code>,
      <code>Text</code>, <code>CDATASection</code>, <code>Comment</code>,
      <code>ProcessingInstruction</code>, or <code>EntityReference</code>
      node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-entity-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is an
      <code>EntityReference</code> node, then it is an
      <a href="#entity-error" id=ee-er-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recursively.</li>
      </ol></li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>Entity</code> node whose
<code>notationName</code> attribute value is <em>not</em> <code>null</code>
(i.e. an unparsed entity)</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>nodeName</code> attribute value as an <code>NCName</code></a>.</li>
    <li><a href="#algorithm-to-validate-a-public-identifier" title="validate a public identifier">Validate
    the <code>publicId</code> attribute value as a public identifier</a>.</li>
    <li><a href="#algorithm-to-validate-a-system-identifier" title="validate a system identifier">Validate
    the <code>systemId</code> attribute value as a system identifier</a>.</li>
    <li>If the <code>systemId</code> attribute value of <var>n</var> is
    <code>null</code>, then raise an
    <a href="#xml-well-formedness-error" id=wfe-uentity-sid><code>xml-well-formedness-error</code></a>.</li>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>notationName</code> attribute value of <var>n</var> as an
    <code>NCName</code></a>.</li>
    <li class=ed>@@ #not-declared Validity constraint: Notation Declared</li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-uentity-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>If <var>n</var> is an <code>EntityReference</code> node</dt>
  <dd>
    <ol>
    <li>An <a href="#entity-error" id=ee-er-node><code>entity-error</code></a>.</li>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>nodeName</code> attribute value as an <code>NCName</code></a>.</li>
    <li>For each node <dfn id=var-er-nc><var>n<sub><var>c</var></sub></var></dfn>
    in the <code>childNodes</code> list of <var>n</var>,
      <ol>
      <li>If <var>n<sub><var>c</var></sub></var> is <em>not</em> an
      <code>Element</code>,
      <code>Text</code>, <code>CDATASection</code>, <code>Comment</code>,
      <code>ProcessingInstruction</code>, or <code>EntityReference</code>
      node, then it is an
      <a href="#xml-well-formedness-error" id=wfe-er-child><code>xml-well-formedness-error</code></a>.</li>
      <li>Otherwise, if <var>n<sub><var>c</var></sub></var> is <em>not</em> an
      <code>EntityReference</code> node, then it is an 
      <a href="#entity-error" id=ee-entity-er><code>entity-error</code></a>.</li>
      <li>Otherwise,
      <a href="#algorithm-to-check-a-node" title="check a node">check
      <var>n<sub><var>c</var></sub></var></a> recursively.</li>
      </ol></li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>Notation</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-ncname">Validate the
    <code>nodeName</code> attribute value as an <code>NCName</code></a>.</li>
    <li><a href="#algorithm-to-validate-a-public-identifier" title="validate a public identifier">Validate
    the <code>publicId</code> attribute value as a public identifier</a>.</li>
    <li><a href="#algorithm-to-validate-a-system-identifier" title="validate a system identifier">Validate
    the <code>systemId</code> attribute value as a system identifier</a>.</li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-notation-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>ProcessingInstruction</code> node</dt>
  <dd>
    <ol>
    <li>If the <code>target</code> attribute value matches to the string
    <code>xml</code> in any case combination, then raise a 
    <a href="#xml-well-formedness-error" id=wfe-pi-xml><code>xml-well-formedness-error</code></a>.</li>
    <li>Otherwise, <a href="#algorithm-to-validate-an-ncname">validate the
    <code>target</code> attribute value as an <code>NCName</code></a>.</li>
    <li>Then,
    <a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">validate
    the <code>data</code> attribute value as an <abbr>XML</abbr> character
    data</a>.</li>
    <li>If the <code>data</code> attribute value contains a string
    <code>?></code>, then raise a 
    <a href="#xml-well-formedness-error" id=wfe-pi-pic><code>xml-well-formedness-error</code></a>.</li>
    <li>If the <code>data</code> attribute value starts with either
    <code class=char>U+0009</code> <code class=charname>CHARACTER
    TABULATION</code>, <code class=char>U+000A</code> <code class=charname>LINE
    FEED</code>, <code class=char>U+000D</code> <code class=charname>CARRIAGE
    RETURN</code>, or <code class=char>U+0020</code>
    <code class=charname>SPACE</code> character, then raise a
    <a href="#round-trip-error" id=rte-pi-s><code>round-trip-error</code></a>.</li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, then raise an
    <a href="#xml-well-formedness-error" id=wfe-pi-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>If <var>n</var> is a <code>Text</code> node</dt>
  <dd>
    <ol>
    <li><a href="#algorithm-to-validate-an-xml-character-data" title="validate an XML string">Validate the 
    <code>data</code> attribute value as an <abbr>XML</abbr> character
    data</a>.</li>
    <li>If the <code>childNodes</code> list of <var>n</var> contains
    any nodes, they are in
    <a href="#xml-well-formedness-error" id=wfe-text-child><code>xml-well-formedness-error</code></a>.</li>
    </ol>
  </dd>
<dt>Otherwise</dt>
  <dd><span class=ed>xml-well-formedness-error?  unknown-error?</span></dd>
</dl>

</div>

</div>

<div id=classes class=section>
<h2>Character Classes</h2>

<p>This section defines a couple of character classes.
These classes are referred to by algorithms specified above.</p>

<p>Character class <dfn id=class-Char10><code>Char10</code></dfn> 
contains the following characters:</p>
<ul>
<li><code class=char>U+0009</code> <code class=charname>CHARACTER
TABULATION</code></li>
<li><code class=char>U+000A</code> <code class=charname>LINE FEED</code></li>
<li><code class=char>U+000D</code> <code class=charname>CARRIAGE
RETURN</code></li>
<li><code class=char>U+0020</code> <code class=charname>SPACE</code>
.. <code class=char>U+D7FF</code></li>
<li><code class=char>U+E000</code> .. <code class=char>U+FFFD</code>
<code class=charname>REPLACEMENT CHARACTER</code></li>
<li><code class=char>U+10000</code> .. <code class=char>U+10FFFF</code></li>
</ul>
<div class="note memo">
<p>This character class contains all characters allowed in the production rule
<a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NT-Char"><code>Char</code></a>
of <abbr>XML</abbr> 1.0
<cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite>.</p>
</div>

<p>Character class <dfn id=class-CompatChar10><code>CompatChar10</code></dfn> 
contains the following characters:</p>
<ul>
<li class=ed>@@ <q>Document authors are encouraged to avoid "compatibility characters", as defined in section 6.8 of [Unicode @@ Unicode 2.0 @@] (see also D21 in section 3.6 of [Unicode3]).</q></li>
</ul>

<p>Character class <dfn id=class-ControlChar10><code>ControlChar10</code></dfn> 
contains the following characters:</p>
<ul>
<li><code class=char>U+007F</code> <code class=charname>DELETE</code> ..
<code class=char>U+0084</code> <code class=charname>INDEX</code></li>
<li><code class=char>U+0086</code> <code class=charname>START OF SELECTED
AREA</code> .. <code class=char>U+009F</code> <code class=charname>APPLICATION
PROGRAM COMMAND</code></li>
<li><code class=char>U+FDD0</code> .. <code class=char>U+FDEF</code></li>
<li><code class=char>U+1FFFE</code> .. <code class=char>U+1FFFF</code></li>
<li><code class=char>U+2FFFE</code> .. <code class=char>U+2FFFF</code></li>
<li><code class=char>U+3FFFE</code> .. <code class=char>U+3FFFF</code></li>
<li><code class=char>U+4FFFE</code> .. <code class=char>U+4FFFF</code></li>
<li><code class=char>U+5FFFE</code> .. <code class=char>U+5FFFF</code></li>
<li><code class=char>U+6FFFE</code> .. <code class=char>U+6FFFF</code></li>
<li><code class=char>U+7FFFE</code> .. <code class=char>U+7FFFF</code></li>
<li><code class=char>U+8FFFE</code> .. <code class=char>U+8FFFF</code></li>
<li><code class=char>U+9FFFE</code> .. <code class=char>U+9FFFF</code></li>
<li><code class=char>U+AFFFE</code> .. <code class=char>U+AFFFF</code></li>
<li><code class=char>U+BFFFE</code> .. <code class=char>U+BFFFF</code></li>
<li><code class=char>U+CFFFE</code> .. <code class=char>U+CFFFF</code></li>
<li><code class=char>U+DFFFE</code> .. <code class=char>U+DFFFF</code></li>
<li><code class=char>U+EFFFE</code> .. <code class=char>U+EFFFF</code></li>
<li><code class=char>U+FFFFE</code> .. <code class=char>U+FFFFF</code></li>
<li><code class=char>U+10FFFE</code> .. <code class=char>U+10FFFF</code></li>
</ul>
<div class="note memo">
<p>This character class contains the characters listed in the Note in
<a href="http://www.w3.org/TR/2006/REC-xml-20060816/#charsets">Section 2.2</a>
of <abbr>XML</abbr> 1.0
<cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite>,
as amended by
<a href="http://www.w3.org/XML/xml-V10-4e-errata#E02">errata</a>.</p>
</div>

<p>The character class <dfn id=class-NameStartChar10><code>NameStartChar10</code></dfn> 
contains the following characters:</p>
<ul class=ed>
</ul>
<div class="note memo">
<p>This character class contains all characters allowed as the first character
of a string matching to the production rule
<a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NT-Name"><code>Name</code></a>
of <abbr>XML</abbr> 1.0
<cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite>.</p>
</div>

<p>The character class <dfn id=class-NameChar10><code>NameChar10</code></dfn> 
contains the following characters:</p>
<ul>
<li>The characters in the character class
<a href="#class-NameStartChar10">NameStartChar10</a>.</li>
<li class=ed></li>
</ul>
<div class="note memo">
<p>This character class contains all characters allowed as the second
character of a string matching to the production rule
<a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NT-Name"><code>Name</code></a>
of <abbr>XML</abbr> 1.0
<cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite>.</p>
</div>

<p>The character class <dfn id=class-PubidChar><code>PubidChar</code></dfn>
contains the following characters:</p>
<ul>
<li><code class=char>U+0009</code> <code class=charname>CHARACTER 
TABULATION</code></li>
<li><code class=char>U+000A</code> <code class=charname>LINE FEED</code></li>
<li><code class=char>U+000D</code> <code class=charname>CARRIAGE
RETURN</code></li>
<li><code class=char>U+0020</code> <code class=charname>SPACE</code></li>
<li><code class=char>U+0021</code> <code class=charname>EXCLAMATION MARK</code>
(<code class=char>!</code>)</li>
<li><code class=char>U+0023</code> <code class=charname>DOLLAR SIGN</code>
(<code class=char>$</code>)</li>
<li><code class=char>U+0024</code> <code class=charname>NUMBER SIGN</code>
(<code class=char>#</code>)</li>
<li><code class=char>U+0025</code> <code class=charname>PERCENT SIGN</code>
(<code class=char>%</code>)</li>
<li><code class=char>U+0027</code> <code class=charname>APOSTROPHE</code>
(<code class=char>'</code>)</li>
<li><code class=char>U+0028</code> <code class=charname>LEFT PARENTHESIS</code>
(<code class=char>(</code>)</li>
<li><code class=char>U+0029</code> <code class=charname>RIGHT
PARENTHESIS</code> (<code class=char>)</code>)</li>
<li><code class=char>U+002A</code> <code class=charname>ASTERISK</code>
(<code class=char>*</code>)</li>
<li><code class=char>U+002B</code> <code class=charname>PLUS SIGN</code>
(<code class=char>+</code>)</li>
<li><code class=char>U+002C</code> <code class=charname>COMMA</code>
(<code class=char>,</code>)</li>
<li><code class=char>U+002D</code> <code class=charname>HYPHEN-MINUS</code>
(<code class=char>-</code>)</li>
<li><code class=char>U+002E</code> <code class=charname>FULL STOP</code>
(<code class=char>.</code>)</li>
<li><code class=char>U+002F</code> <code class=charname>SOLIDUS</code>
(<code class=char>/</code>)</li>
<li><code class=char>U+0030</code> <code class=charname>DIGIT ZERO</code>
(<code class=char>0</code>) .. <code class=char>U+0039</code>
<code class=charname>DIGIT NINE</code> (<code class=char>9</code>)</li>
<li><code class=char>U+003A</code> <code class=charname>COLON</code>
(<code class=char>:</code>)</li>
<li><code class=char>U+003B</code> <code class=charname>SEMICOLON</code>
(<code class=char>;</code>)</li>
<li><code class=char>U+003D</code> <code class=charname>EQUAL SIGN</code>
(<code class=char>=</code>)</li>
<li><code class=char>U+003F</code> <code class=charname>QUESTION MARK</code>
(<code class=char>?</code>)</li>
<li><code class=char>U+0040</code> <code class=charname>COMMERCIAL AT</code>
(<code class=char>@</code>)</li>
<li><code class=char>U+0041</code> <code class=charname>LATIN CAPITAL LETTER
A</code> (<code class=char>A</code>) .. <code class=char>U+005A</code>
<code class=charname>LATIN CAPITAL LETTER Z</code> 
(<code class=char>Z</code>)</li>
<li><code class=char>U+005F</code> <code class=charname>LOW LINE</code>
(<code class=char>_</code>)</li>
<li><code class=char>U+0061</code> <code class=charname>LATIN CAPITAL LETTER
A</code> (<code class=char>A</code>) .. <code class=char>U+007A</code>
<code class=charname>LATIN CAPITAL LETTER Z</code> 
(<code class=char>Z</code>)</li>
</ul>
<div class="note memo">
<p>This character class contains all characters allowed in the production rule
<a href="http://www.w3.org/TR/2006/REC-xml-20060816/#NT-PubidChar"><code>PubidChar</code></a>
of <abbr>XML</abbr> 1.0
<cite class="bibref normative">[<a href="#ref-XML10">XML10</a>]</cite>.</p>
</div>

</div>

<div id="references" class="section reference">
<h2>References</h2>

<div id="normative-references" class="section normative reference">
<h3>Normative References</h3>

<dl>
<dt id=ref-DOM3CORE>DOM3CORE</dt>
  <dd class=ed>@@ W3C DOM Level 3 Core</dd>
<dt id=ref-DOMDTDEF>DOMDTDEF</dt>
  <dd class=ed>@@ manakai's extension to DOM for document type definitions</dd>
<dt id="ref-KEYWORDS">KEYWORDS</dt>
  <dd><cite><a href="urn:ietf:rfc:2119">Key words for use in 
  <abbr>RFCs</abbr> to Indicate Requirement Levels</a></cite>,
  <abbr title="Internet Engineering Task Force">IETF</abbr> 
  <a href="urn:ietf:bcp:14"><abbr title="Best Current Practice">BCP</abbr> 
  14</a>, <abbr title="Request for Comments">RFC</abbr> 2119, 
  <time datetime=1997-03>March 1997</time>.
  <em>This</em> version of the specification is referenced.</dd>
<dt id=ref-INFOSET>INFOSET</dt>
  <dd class=ed>@@</dd>
<dt id=ref-XML10">XML10</dt>
  <dd><cite><a href="http://www.w3.org/TR/2006/REC-xml-20060816">Extensible
  Markup Language (<abbr>XML</abbr>) 1.0 (Fourth Edition)</a></cite>,
  <abbr>W3C</abbr> Recommendation, <time datetime=2006-08-16>16 August 
  2006</time>, edited in place <time datetime=2006-09-29>29 September
  2006</time>.  Tje latest version of the specification is available at
  <code class=uri>&lt;<a href="http://www.w3.org/TR/xml">http://www.w3.org/TR/xml</a>&gt;</code>.
  <em>This</em> version of the specification is referenced.</dd>
<dt id=ref-XML11>XML11</dt>
  <dd class=ed>@@</dd>
</dl>
</div>

<div id="informative-references" class="section informative reference">
<h3>Non$B!>(Bnormative References</h3>

<dl class=ed>
<dt id=ref-CSS>CSS</dt>
  <dd><cite><a href="http://www.w3.org/TR/2007/CR-CSS21-20070719">Cascading
  Style Sheets Level 2 Revision 1 (<abbr>CSS</abbr> 2.1)
  Specification</a></cite>, 
  <abbr title="World Wide Web Consortium">W3C</abbr> Candidate
  Recommendation, <time datetime=2007-07-19>19 July 2007</time>.
  Work in progress.  The latest version of the specification is
  available at 
  <code class=URI>&lt;<a href="http://www.w3.org/TR/CSS21">http://www.w3.org/TR/CSS21</a>></code>.</dd>
<dt id=ref-CSSOM>CSSOM</dt>
  <dd><cite><a href="http://dev.w3.org/cvsweb/~checkout~/csswg/cssom/Overview.html?rev=1.55&amp;content-type=text/html;%20charset=utf-8">Cascading
  Style Sheets Object Model (<abbr>CSSOM</abbr>)</a></cite>,
  <abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft,
  <time datetime=2007-06-18>18 June 2007</time>.  Work in progress.
  The latest Editor's Draft of the specification is available at
  <code class=URI>&lt;<a href="http://dev.w3.org/csswg/cssom/Overview.html">http://dev.w3.org/csswg/cssom/Overview.html</a>></code>.</dd>
<dt id=ref-HTML5>HTML5</dt>
  <dd><cite><a href="http://whatwg.org/html5"><abbr>HTML</abbr> 5</a></cite>,
  <abbr title="Web Hypertext Application Technology Working Group">WHATWG</abbr>
  Working Draft.  Work in progress.</dd>
<dt id=ref-SAPI>SAPI</dt>
  <dd><cite><a href="http://dev.w3.org/cvsweb/~checkout~/2006/webapi/selectors-api/Overview.html?rev=1.28&amp;content-type=text/html;%20charset=utf-8">Selectors <abbr>API</abbr></a></cite>,
  <abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft,
  <time datetime=2007-08-29>29 August 2007</time>.  Work in progress.
  The latest Editor's Draft of the specification is available at
  <code class=URI>&lt;<a href="http://dev.w3.org/2006/webapi/selectors-api/Overview.html">http://dev.w3.org/2006/webapi/selectors-api/Overview.html</a>></code>.
  The latest published version of the specification is available at
  <code class=URI>&lt;<a href="http://www.w3.org/TR/selectors-api/">http://www.w3.org/TR/selectors-api/</a>></code>.</dd>
<dt id=XBL2>XBL2</dt>
  <dd><cite><a href="http://www.mozilla.org/projects/xbl/xbl2.html"><abbr>XBL</abbr>
  2.0</a></cite>, Mozilla.org, <time datetime=2007-03-15>15 Mar 2007</time>.
  Work in progress.  The latest
  <abbr title="World Wide Web Consortium">W3C</abbr>$B!>(Bpublished
  version of the specification is available at
  <code class=URI>&lt;<a href="http://www.w3.org/TR/xbl/">http://www.w3.org/TR/xbl/</a>></code>.</dd>
<dt id=ref-XML5>XML5</dt>
  <dd class=ed>@@</dd>
</dl>
</div>

</div>

</body>
</html>