< character is not followed
by tag name or by a ! character.A < (U+003C LESS-THAN
- SIGN) character which is not part of any markup appears
- in the input stream.
A < (U+003C
+ LESS-THAN SIGN) character which is not part
+ of any markup appears in the input stream.
The < character as a data character must
be escaped as:
-<lt;
+<
The string &# must be the first two characters
- NUMBER SIGN) character must be the first two characters
of a reference:
To represent &# as data characters, use
- named entity reference:
+ a named entity reference for the & character:
&#
@@ -116,7 +115,7 @@
of the code point of the character to be referenced.
To represent &#x as data characters, use
- named entity reference:
+ a named entity reference for the & character:
&#x
@@ -135,7 +134,8 @@
declaration.
-$0.There are more than one attributes with the same name in a tag. The document is non-conforming.
@@ -175,8 +175,8 @@Instead of XML style sheet,
PIs, you must
use the HTML link element whose rel
- attribute is set to stylesheet (or alternate
- stylesheet for an aleternate style sheet).
stylesheet (or
+ alternate stylesheet for an aleternate style sheet).
Web browsers will parse processing instructions as bogus comments. Some legacy Web browsers, such as IE:mac and @@ -215,15 +215,25 @@
<$0>
- is not allowed in body.body element.
The start or end tag of an element, which
cannot be a descendant of body element, appears
in the input stream while the body element has been opened.
The document is non-conforming.
<head>
+ is not allowed in the head element.There is a start tag <head> in the
+ <head> element. The document is non-conforming.
In an HTML document there must not be more than
+ one head element, therefore no more than one
+ start tag <head> can appear in the input stream.
<$0>
- is not allowed in table.table element.
The start or end tag of an element, which
cannot be a child of table element, appears
in the input stream while the table element has been opened
@@ -260,7 +270,7 @@
these start tags, it must be explicitly specified.
DOCTYPE.The document does not start with a DOCTYPE.
The document is non-conforming.
<html> tag is not
+ the first start tag.There is a start tag of the html element
+ that it not the first start tag in the input stream.
+ The document is non-conforming.
In an HTML document, there cannot be more than one
+ html element and therefore there cannot be
+ more than one <html> tag. In addition,
+ nothing can be placed before the <html> tag
+ except a DOCTYPE, white space characters,
+ and comments.
The document contains a DOCTYPE declaration
- that is different from HTML5 DOCTYPE (i.e. <!DOCTYPE
- HTML>). The document is non-conforming.
DOCTYPE (i.e.
+ <!DOCTYPE HTML>). The document is non-conforming.
The document might or might not be conformant to some version of HTML. However, conformance to any HTML @@ -314,24 +338,20 @@ context. The document is non-conforming.
Possible causes: -
a or span)A data character cannot be a child
- of certain sectioning elements such as body,
- section, and blockquote.
Any inline-level content must be put
- in e.g. paragraph element such as p.
div or hn)Though some elements such as div,
- li, and td allow
- either one 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 p.
A data character cannot be a child
+ of certain sectioning elements such as body,
+ section, and blockquote.
Any inline-level content must be put
+ in e.g. paragraph element such as p.
Though some elements such as div,
+ li, and td allow
+ either one 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 p.
Possible causes: -
a or span)a, progress, or imgAn inline-level element cannot be a child
of certain sectioning elements such as body,
section, and blockquote.
Any inline-level content must be put
in e.g. paragraph element such as p.
div or hn)div, hn, or
+ sectionThough some elements such as div,
li, and td allow
either one 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 p.
html elementnoscript elementnoscript element is allowed only in the context
+ where a block-level or inline-level content is expected
+ and in the head element.
+ It cannot be used in e.g. ul, table,
+ or select.html element
+ that is the root element of an XHTML documentIn an XHTML document, the root html
element must have an xmlns attribute
whose value is set to
@@ -394,6 +422,15 @@
$0
+ element before this element.There must be an element before another element, but there + is not. The document is non-conforming.
+ +For example, there must be a dt element
+ before any dd element.
To specify natural language information in HTML document,
use lang attribute instead.
XHTML 1.0 Appendix C was encouraged to specify both
+ lang and xml:lang attributes with
+ the same value. Such a duplication has no effect in practice.
+ Use only one of lang (in HTML) or xml:lang (in
+ XML).
{@} is not one
+ of them.
$0
is non-conforming.The specified link type is non-conforming. The entire document - is non-conforming.
+The specified link type is non-conforming, and therefore + the document is non-conforming.
-For example, in place of non-conforming link type copyright
- you must use link type license.
contentsindex.copyrightlicense.homeindex.startfirst.tocindex.{@} is reserved.The specified browsing context name is reserved. + The document is non-conforming.
-Names of browsing contexts starting with _
+ (U+005F LOW LINE)
+ are reserved so that it must not be used.
Old version of HTML, non-HTML markup languages, and
+ Web browsers define or implements special reserved
+ browsing context names _blank,
+ _main, and _replace.
+ However, they are not conforming attribute values.
td or
th) in the last row.rowspan attribute
+ results in creating a table row that does not contain
+ any cell anchored to it.The rowspan 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.
For example, the table below is non-conforming: +
+<table>
+<tbody>
+<tr><td rowspan=2></td></tr>
+</tbody>
+</table>
+ ... is non-conforming, since the second row contains only
+ a cell that spans the first and the second rows.
+ x- or x.)
+{@}: An obsolete
subtype is used.{@}: A private
+ (x- or x.) subtype is used.{@}: The subtype is
+ not registered to IANA.The specified value does not satisfy the syntactical requirements + for IRI references. The document is non-conforming.
+ +Possible causes: +
(U+0020
+ SPACE) character cannot be
+ used in IRI references.The scheme part of the IRI is written in uppercase letter.
+ +Uppercase scheme names are not required to be processed + correctly.
+ +