sure.. you can..
you'd need to edit libs/html.inc.php
and add after the signature restriction
if ($type == "signature") {
$this->bbcode_parser->disallow_tag("custom");
}
if ($type == "shoutbox") {
$this->bbcode_parser->disallow_tag("custom");
$this->bbcode_parser->disallow_tag("code");
$this->bbcode_parser->disallow_tag("php");
$this->bbcode_parser->disallow_tag("noparse");
$this->bbcode_parser->disallow_tag("quote");
$this->bbcode_parser->disallow_tag("post");
$this->bbcode_parser->disallow_tag("spoiler");
}
you'd put in whatever tags you would NOT like to be allowed in the shoutbox..
then go to libs/bbcode.inc.php and not return right away if 'shoutbox' but fall thru and parse the stuff..
one additional thing is for parsing 'magic urls', to not include the long string of the url, but to make it a clickable short link, like '[ Click Me ]'
then it works.. i've done this for my Shoutbox on a couple of sites..
one further thing i did, since i allow img's in the shoutbox, i added some css, to shrink down the images to a max-width kinda dealio so as to not 'break' the shoutbox..