fr_derefrule
if (fr_derefrule(&fp, ifs) == 0)
(void)fr_derefrule(&f, ifs);
(void)fr_derefrule((frentry_t **)datap, ifs);
(void) fr_derefrule(&fr, ifs);
(void)fr_derefrule(&fr, ifs);
(void) fr_derefrule(&fr, ifs);
(void)fr_derefrule(&nat->nat_fr, ifs);
(void)fr_derefrule(&is->is_rule, ifs);
extern int fr_derefrule __P((frentry_t **, ipf_stack_t *));