SoniEx2 SoniEx2 - 2 months ago 8
HTML Question

Does XHTML5 require a DOCTYPE/DTD?

I'm creating a language that translates to XML, and it doesn't support DOCTYPE/DTD. Can I use XHTML5 without having to specify

<!DOCTYPE html>
, or am I stuck with having to implement DOCTYPE/DTD? I'd rather not, mainly to avoid language complexity.


The WHATWG says:

In the XML syntax, any doctype declaration may be used, or it may be omitted altogether.

and also:

The <!DOCTYPE html> definition is optional, but (...)

And the W3C says:

[The Document Type Declaration] may optionally be used within the XHTML syntax, but (...)

so we can safely assume that the DOCTYPE declaration is optional.
Also, a quick and dirty test shows that in the latest browsers, there is no discernible difference in handling files with or without a doctype declaration. As long as the file type is .xml or .xhtml.