Italicizing text surrounded by /'s is annoying.
Let's say, hypothetically (wink) I write something perlish like this and send it off to someone:
if ($cust_id =~ /^r\d+/)
the regular expression will be italicized and the /'s gone.
I tell you what, if this wasn't a hypothetical, and I actually had to do something like this... I would find that slightly annoying. :)