init_filter
void init_filter(char *, int);
init_filter(NULL, verbose);
void init_filter(char *, char *, int);
.init_filter = init_filter,
void (*init_filter)(char *, char *, int);
fops->init_filter(qname, tagname, verbose);
.init_filter = ipf_init_filter,
.init_filter = npf_init_filter,