cperl-vc-rcs-header
cperl-vc-rcs-header is a variable defined in `cperl-mode.el
'.Its value is
("($rcs) = (' $Id$ ' =~ /(\\d+(\\.\\d+)+)/);")
Documentation:
*Special version of `vc-rcs-header' that is used in CPerl mode buffers.
You can customize this variable.