[Gas] dumb perl question

[Sigfried Gold]

The Gas code example has the following section in the main .pm
file:

   no strict 'vars';
   # Globally defined static (CONSTANT) variables go here. Note that this
   # file (and any other use'ed file) is only run at BEGIN time when
   # running under mod_perl and so any calculations are done at server
   # startup rather than at request time.

this implies that there's a way to make static variables in Perl,
which i've heard is the case, but I don't know how to do it.  i
hope i will be pardoned for asking here rather than r'g tfm, but
how do you make static variables in Perl?

thanks
s