I think XHTMLate should be pronounced "stimulate". Anyway, here's a list of WordPress bugs that I think are important for XHTML:
- 3833 - Extra </p> inside blockquote
- 3914, 4746 - Two feeds on Dashboard don't work with application/xhtml+xml
- 4466 - Serve application/xhtml+xml if browser compliant
- 4857 - More issues with wpautop()
- 5144 - Paragraph end-tag wrongly inserted after object tag
- 5250 - wpautop() issue with nested lists
- 5998 - Invalid Unicode characters
I know there are a heap more. I know more will be submitted. This is just what I found when scanning the first few pages of a search for "xhtml".
I've encountered 5144 directly on this blog with my clip art. I've found that I have to start the paragraph right after the <object> tag without a newline. A little annoying, but workaround-able.
Shelley just created Bug 5998 right now. This is a bug for WP accepting illegal Unicode code points like U+FFFE, which Jacques so kindly demonstrated.
Sad/Funny sidenote: When he did this, I ran into the very problem that Mark mentioned years ago and I had to poke my WordPress database option to switch back to text/html for the WordPress admin panel so I could correct Jacques' invalid character. Tail now less bushy...