The following missing or conflicting information caused the validator to perform guesswork prior to validation. If the guess or fallback is incorrect, it may make validation results entirely incoherent. It is highly recommended to check these potential issues, and, if necessary, fix them and re-validate the document.
No Character Encoding Found!
Falling back to
None of the standards sources gave any information on the character encoding
labeling for this document. Without encoding information
it is impossible to reliably validate the document. As a fallback
solution, the "
encoding was used to read the content and attempt to perform the validation,
but this is likely to fail for all non-trivial documents.
The sources used to find encoding information include:
The algorithm defined in Appendix F of the XML 1.0 Recommendation was also used, without success.
Since none of these sources yielded any usable information, reliable validation of this document is not possible. Sorry. Please make sure you specify the character encoding in use.
Specifying a character encoding is typically done by the web server configuration, by the scripts that put together pages, or inside the document itself. IANA maintains the list of official names for character encodings (called charsets in this context). You can choose from a number of encodings, though we recommend UTF-8 as particularly useful.
The W3C I18N Activity has collected a few tips on how to declare the encoding of a Web document.
To quickly check whether the document would validate after addressing the missing character encoding information, you can use the "Encoding" form control earlier in the page to force an encoding override to take effect. "iso-8859-1" (Western Europe and North America) and "utf-8" (Universal, but not commonly used in legacy documents) are common encodings if you are not sure what encoding to choose.
Unable to Determine Parse Mode!
The validator can process documents either as XML (for document types such as XHTML, SVG, etc.) or SGML (for HTML 4.01 and prior versions). For this document, the information available was not sufficient to determine the parsing mode unambiguously, because:
text/html) can be used for XML or SGML document types
<?xml version="1.0"?>) could be found at the beginning of the document.
As a default, the validator is falling back to SGML mode.