PG_KEY1
#define IS_PG_KEY1(ID) ((ID) == PG_KEY1)
((ID) > PG_KEY1 && (ID) <= PG_END)
pg_key1->tag = PG_KEY1;
pgt[0].tag == PG_KEY1) {
case PG_KEY1:
case PG_KEY1:
{ PG_KEY1, LAST_TAG_PG, PG_END },