[Palmer ofShinra]

Actually... you really should read up on the functions Reeve my friend.

As it is, users with HTML enabled can use any VBcode in their title, including IMG.
They may also use smileys.

Users with JUST VBcode allowed cannot use IMG or smileys.

See...

HTML - bbcodeparse2($post[usertitle],1,1,1,1);
No HTML - bbcodeparse2($post[usertitle],0,0,0,1);

The 4 digits represent, in order
Allow HTML (will do an htmlspecialchars() if no)
Allow IMG (will not parse)
Allow Smileys (will not parse)
Allow VBcode (will not parse... kinda pointless to turn off)

The HTML level has them all set to 1 (yes) because, well... if you can use HTML, you can put an image in your title.

But for normal users it's disabled.
If you want to change that, adjust the zeroes to ones as appropriate.