If I understand correctly:
   #;FORM
is equivalent to:
   #|FORM|#
The difference is that the end of the comment is
implicit by the end of the form.  The only advantage
I see it makes it easier for a programmer to comment
a form in or out without having to find the end of the
S-expression.  But how difficult is this, especially
if you're using an editor that supports S-expressions?

On the other hand, the #:FORM syntax is harder for
humans *reading* the code, since it's not visually
obvious where the comment ends.
--
	--Per Bothner
xxxxxx@bothner.com   http://per.bothner.com/