Ian Hickson wrote: > In general you should be able to just implement what the spec says and > then either leave the HTML5 support in (it's unlikely to cause any harm) > or just comment out the support for the new elements, that should be > relatively easy.
Right, this is mostly what I intended to do. But from what I can tell, there's a difference between the design philosophies of HTML 5 and XHTML 2.0; XHTML tries to make everything "extensible" and able to be imported from other places, while HTML 5 attempts to document what exists, and then make sensible additions as necessary. HTML 5 pragmatism makes sense for a user-agent, but the XHTML extensibility is useful for a sanitizer, which doesn't actually have to render anything and needs to support multiple dialects and variants. Cheers, Edward