-Depending on the value of `payby', this may print an invoice (`BILL'), charge
-a credit card (`CARD'), or just add any necessary (pseudo-)payment (`COMP').
+Depending on the value of `payby', this may print or email an invoice (I<BILL>,
+I<DCRD>, or I<DCHK>), charge a credit card (I<CARD>), charge via electronic
+check/ACH (I<CHEK>), or just add any necessary (pseudo-)payment (I<COMP>).