HTML5 Character Encoding Errors

+ + + Character encoding $0 + is not allowed for HTML document. + +

The character encoding used for the document is not allowed + for HTML document. The document is non‐conforming.

+ + + + + Character encoding $0 + should not be used for HTML document. + +

The character encoding used for the document is not recommended + for HTML document. The document is non‐conforming + unless there is any good reason to use that encoding.

+ + + + + Use of UTF-8 is encouraged. + +

Use of UTF-8 as the character encoding of the document is encouraged, + though the use of another character encoding is still conforming.

+ + + + + Conformance for character encoding requirements + cannot be checked. + +

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.

+ + + + + There is no character encoding + declaration. + +

The document does not contain a character encoding + declaration. Unless the character encoding is explicitly + specified in lower‐level protocol, e.g. in HTTP, + or is implied by BOM, there must be a character + encoding declaration. The document is non‐conforming.

+ +

The long character encoding declaration syntax + <meta http-equiv="Content-Type" content="text/html; charset=charset-name"> + is obsolete. The new syntax is:

<meta charset="charset-name">

+ +

Note that the encoding declaration in XML + declaration has no effect for HTML document.

+ + + + + No character encoding metadata is found + in lower‐level protocol nor is there BOM, while + character encoding $0 + is not a superset of ASCII. + +

The document is not labeled with character encoding name + in lower‐level protocol, e.g. in HTTP, and + the document is not begin with BOM. In addition, + the character encoding of the document is not a superset of + ASCII. The document is non‐conforming.

+ +

Unless there is a BOM, the character encoding + for the document must be specified in e.g. HTTP‐level, + as:

Content-Type: text/html; charset=charset-name

+ +

Existence of HTML character encoding declaration, i.e. + <meta charset="charset-name">, + does not allow to omit charset parameter + for HTML document encoded in non‐ASCII + compatible encoding.

+ +

Character encodings Shift_JIS, Windows-31J, + and ISO-2022-JP are not a superset of + ASCII for the purpose of HTML conformance.

+ + + + + While parsing the document as + $0, a character encoding declaration specifying + character encoding as $1 is found. The document + is reparsed. + +

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.

+ +

The document will be reparsed from the beginning. Some error + or warning might be reported again.

+ +

These are suggestions to avoid this warning:

Specify charset parameter in the Content-Type + field in the HTTP header, as: +
```
Content-Type: text/html; charset="charset-name"
```
Put the character encoding declaration + (<meta charset="charset-name">) + just after <head> start tag.
Use UTF-8.

+ + +

HTML5 Parse Errors in Tokenization Stage

@@ -889,6 +1017,87 @@

Attribute Value Errors

+ + Character encoding name $0 + is not registered. + +

The specified character encoding name is not registered to + IANA. Use of registered character encoding name + is a good practice to facilitate interoperability.

+ +

EUC-TW: EUC-TW is not registered. Unfortunately, there + is no registered name for that character encoding. Use + Big5 encoding with character encoding name Big5 + if it is enough to represent the document.
ISO-2022-JP-1: ISO-2022-JP-1 is not registered, nevertheless + this character encoding name is documented in + RFC 2237. Use + ISO-2022-JP-2 instead, since that character encoding + is a superset of ISO-2022-JP-1.
ISO-2022-JP-3, ISO-2022-JP-3-plane1: These names are not registered and obsoleted in favor of + ISO-2022-JP-2004 and + ISO-2022-JP-2004-plane1.
ISO-2022-JP-2003, + ISO-2022-JP-2003-plane1: These names are not registered and corrected to + ISO-2022-JP-2004 and + ISO-2022-JP-2004-plane1.
ISO-2022-JP-2004, + ISO-2022-JP-2004-plane1: These names are not registered. Unfortunately, there is + no registered name for these character encodings.
UTF-8N: UTF-8N is not registered. Character encoding + name UTF-8 represents UTF-8 encoding with or + without BOM.

+ +

WARNING: 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.

+ + + + + $0 is a private + character encoding name. + +

The specified character encoding name is a private name and + not registered to IANA. Use of registered character + encoding name is a good practice to facilitate interoperability.

+ +

x-euc-jp: Use EUC-JP for the Japanese EUC + character encoding.
x-sjis: Use Shift_JIS for standard Shift encoding scheme of + JIS coded character set, or Windows-31J + for Microsoft standard character set as implemented by + Microsoft Windows.

+ + + + + The specified value is syntactically not a + character encoding name. + +

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.

Character encoding name is a string of ASCII + printable characters, up to 40 characters.

+ + + This attribute only allow a limited set of @@ -922,15 +1131,15 @@ - Charset declaration syntax + Character encoding declaration syntax <meta http-equiv="Content-Type" content="text/html; charset=charset-name"> is obsolete. -

Old long charset declaration syntax +

Old long character encoding declaration syntax <meta http-equiv="Content-Type" content="text/html; charset=charset-name"> is in use. The document is non‐conforming.

The new charset declaration syntax is: +

The new character encoding declaration syntax is:

<meta charset="charset-name">

@@ -985,6 +1194,18 @@ + + Character encoding name $1 + is different from document character encoding + $0. + +

The specified character encoding name is different from + the character encoding of the document. The document + is non‐conforming.

+ + + Browsing context name @@ -1232,6 +1453,70 @@

Stability Information

+ + + This element is in the + call for implementation stage. + +

The element is in the call for implementation stage.

+ +

Usually, using the element is safe. However, it is a new feature + so that it might not be implemented correctly. If it is found that + the feature is hard or impossible to implement, the feature + might be revised, or in some case it might be dropped.

+ +

Elements defined by Atom 1.0 (IETF Proposed Standard), and XBL 2.0 + (W3C Candidate Recommendation) belong to this class.

+ + + + + This element is in the last + call for comments stage. + +

The element is in the last call for comments stage.

+ +

The element is relatively mature, though the standardization + is not done yet. It may be used for experiments. Since it is a new + feature, it might not be implemented correctly or at all. If it is + found that the feature is hard or impossible to implement, the feature + might be revised or might be dropped.

+ +

Elements defined by Web Forms 2.0 as well as some elements + defined by HTML5 belong to this class.

+ + + + + This element is documented in a working + draft. + +

The element is documented in a working or editor's draft + and not yet completed.

+ +

The element should not be used for any practical purpose. + The feature might be drastically changed later or might be + entirely removed.

+ +

Most of new elements defined by HTML5 belong to this class.

+ + + + + This element is not part of any + standard the conformance checker knows. + +

The element is not part of any standard or draft the conformance + checker is aware of.

+ +

The element should not be used for any practical purpose unless + there is really a standard that defines the element.

+ + +

Unsupported Messages

@@ -1354,7 +1639,15 @@ It does not affect to the conformance of the document, and may sometimes be inappropriate. - + +Information +Conforming. +An informational message just provides an additional information +on the feature used in the document or the status of the retrieval +or so on. +It does not affect to the conformance of the document. + + Not supported Unknown. Some feature that is not supported by the conformance checker @@ -1367,7 +1660,7 @@

License of This Document

@@ -1375,6 +1668,6 @@ and/or modify it under the same terms as Perl itself.