if a code gets hardset then i suppose you can try clearing them but if it stays persistant then the problem is still there and will not clear until it is resolved.

as far as urls go on this site they have it setup to remove any email addresses or website urls that are posted in the main post areas.
you can add a few spaces between the prefix's and then use preview post so see how it looks. If it's still blocked out in preview then work on it some more till you get it to show. you can put your email address in your signature in your personal information and it will allow that to show but they just dont want a bunch of outside websites being posted in the forum i suppose for our own security. just because i have my email in my signature some bots and other folks do feel the need to spam me from here so i do get alot of spam emails from business's trying to sell me stuff but thats what the email filter is for in my email client, they wont do it but once ;o)