Forums use some seriously antiquated code

Hey WPMUdev,

I don't think I'd realized the relative age of this code. It blew my mind when I want to start formatting the generated code in CSS and I found a <center> tag on the search form.

Really? That's been obsolete since XHTML 4 dropped. I realize it's probably one of those things in line for a complete rewrite but, wow.

Please pull the code into line with XHTML/HTML5 standards.