EpubCCEPUBCheck HTM-009: obsolete DOCTYPE to remove
Updated:
EPUBCheck HTM-009 is an error message: “The DOCTYPE provided is obsolete or irregular and can be removed.” A document's DOCTYPE is obsolete or irregular and can simply be removed. EPUB only allows a few external identifiers in DOCTYPEs (for MathML, the NCX and SVG 1.1); anything else is reported.
The official message
The DOCTYPE provided is obsolete or irregular and can be removed.
- Default severity
- Error. The EPUB breaks a rule of the specification and is invalid. Stores and Send to Kindle may reject it, and EPUBCheck exits with status 1.
- EPUBCheck version
- 5.4.0
Typical causes
- Old DOCTYPEs kept from earlier versions of the book, such as XHTML 1.1 or HTML 4 identifiers.
- A DOCTYPE added by an editor or converter that uses a web template for every file.
How to fix it
- Open the file EPUBCheck names (the message gives the path, line and column) in a text or EPUB editor such as Sigil, or unzip the EPUB and open it there.
- Remove the DOCTYPE line, or replace it with
<!DOCTYPE html>in XHTML content documents. - Check that the file still has its XML declaration and the html element with the XHTML namespace
xmlns="http://www.w3.org/1999/xhtml". - Rebuild the EPUB and run EPUBCheck again to confirm the message is gone.
When it's not this
If EPUBCheck tells you which DOCTYPE it expected instead, the message is HTM-004.
Terms used here
Other HTM messages
HTM-010Namespace "…" is unusual for the prefix "epub".HTM-007Empty or whitespace-only value of attribute ssml:ph.HTM-011Entity is undeclared.HTM-004Irregular DOCTYPE: found "…", expected "…".HTM-003External entities are not allowed in EPUB v3 documents. External entity declaration found: ….HTM-001Any publication resource that is an XML-based media type must be a valid XML 1.0 document. XML version found: ….
Sources
Message text and severity from EPUBCheck 5.4.0 (W3C, BSD-3-Clause). Explanation by EpubCC.