The pfiles uses a revision system, which allows admins to update pfiles without to much hazzle. In jobo_util.c you'll find a function called update_revision() and in merc.h you'll find a declartion of CURRENT_REVISION. Each time you update the pfile revision, you just increase the CURRENT_REVISION by one in merc.h, and add the revision update in jobo_util.c (theres an example on how to use it, commented out in the code).