Mostly due to the tag-closing behaviour. I guess I don't really understand this; best practice in HTML is to close tags and quote attributes just as in XHTML.

Mostly due to the tag-closing behaviour. I guess I don't really understand this; best practice in HTML is to close tags and quote attributes just as in XHTML. The only difference is XHTML requires it. As for self-closing tags, the only one I use, at all, is <img>, and I'm perfectly OK with having to handle that (largely because I don't; there are already libraries which will generate my HTML for me).