Sectorgame

Just writing a Perl CGI script for a music submit form and was wondering what characters besides letters, numbers, periods(.), underscores(_) and hyphens(-) can be used in email addresses?

I'm also very new with sub-domains, can they include special characters?

As a general rule, I avoid those sort of things when working with Web-stuff, not that I know anything about Perl, but considering the old 'Space Bar' to '%20' problem still pops up from time to time, its best to avoid the risk