On Sat, Dec 18, 2021 at 01:58:30PM -0800, Per Bothner wrote: > > > On 12/18/21 13:01, Patrice Dumas wrote: > > It seems that it does not change the work required compared to XHTML 1.1 > > which is to have a correct XML document. Something I cannot find, > > however, is what to put at the beginning to be able to check validity > > of the resulting document if it is HTML5 XML. Can you please tell me? > > As far as I can tell, you don't need to put anything at the start: > https://html.spec.whatwg.org/multipage/xhtml.html#the-xhtml-syntax > A validator should allow you to specify what you want to validate against. > > This should be OK: > > <?xml version="1.0" encoding="UTF-8"?> > <!DOCTYPE html>
I tried that with the https://validator.w3.org/, also using .xhtml as extension as it seems that it is what makes the w3c validator consider that it is XML, with and without <?xml?>, and I get: Schema Error: XML document with no namespace; cannot determine any schema to use for validation. Any idea on what is wrong? > For "polyglot" output, leave off the <?xml?> declaration. Also, what could I use for offline validation? The w3c-markup-validator package does not seem to handle HTML5, and the vnu https://validator.github.io/validator/ validator does not seem to be packages in debian. -- Pat
