S_STACK
stack = LF_ISSET(S_STACK);
stack = F_ISSET(dbp, DB_BT_RECNUM) && LF_ISSET(S_STACK);
#define S_DELETE (S_WRITE | S_DUPFIRST | S_DELNO | S_EXACT | S_STACK)
#define S_INSERT (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK)
#define S_KEYFIRST (S_WRITE | S_DUPFIRST | S_PAST_EOF | S_STACK)
#define S_KEYLAST (S_WRITE | S_DUPLAST | S_PAST_EOF | S_STACK)