$ perl -c -e ' my $c_ref; $c_ref = "foo"'
-e syntax OK
The moral is that you should always use warnings and strict. But, even if you don't (or can't), $c_ref is still obviously wrong if you're looking at code following the HungDamian naming convention.
(Personally, I think we should come up with a better name than that - Damian may like this one too much. And his publicist may not ;-})
PS - I'm not attempting to convert anyone to this style of naming. I don't use it myself, and I'm not sure I'm going to start, either. Someone asked why Damian would have suggested this, and I answered. Personally, if I were to start, it'd be using an 'r' prefix rather than a '_ref' suffix.