I'm with Randal on this one. Why not just add the following comment?
# match a number using regular expreeion - for more
# information, read "Learning Perl" or "Programming Perl",
# both published by O'Reilly at:
I mean, regular expressions are a foundation of Perl. Letting people loose on a Perl script who don't know what a regular expression is, is like letting a graphic designer build web pages without seeing or understanding the underlying code...
Ah, yes, well, ahem...