just to add....why do members user names go italicy after 500 or so posts?....is it to signify they are a proper member?....also some people have posted 2000 times but their user name hasnt changed...how?.....

sos for being boring but im interested
 
Italics signify senior member which means extra PM space and bold signifies mods / admins

*edit* missed the other bit of your question.

I believe you need 500 posts and a year on SCN to become a senior member