+Options may include:
+
+B<amount>: the amount to be paid; defaults to the customer's balance minus
+any payments in transit.
+
+B<payby>: the payment method; defaults to cust_main.payby
+
+B<realtime>: runs this as a realtime payment instead of adding it to a
+batch. Deprecated.
+
+B<invnum>: sets cust_pay_batch.invnum.
+
+B<address1>, B<address2>, B<city>, B<state>, B<zip>, B<country>: sets
+the billing address for the payment; defaults to the customer's billing
+location.
+
+B<payinfo>, B<paydate>, B<payname>: sets the payment account, expiration
+date, and name; defaults to those fields in cust_main.
+