Supported format keys (defined in the specified FS::pay_batch module) are:
-I<filetype> - CSV, fixed, variable, XML
+I<filetype> - required, can be CSV, fixed, variable, XML
-I<fields> - list of field names for each row/line
+I<fields> - required list of field names for each row/line
I<formatre> - regular expression for fixed filetype
-I<parse> - for variable filetype
+I<parse> - required for variable filetype
-I<xmlkeys> - for XML filetype
+I<xmlkeys> - required for XML filetype
-I<xmlrow> - for XML filetype
+I<xmlrow> - required for XML filetype
I<begin_condition> - sub, ignore all lines before this returns true
I<skip_condition> - sub, skip lines when this returns true
-I<hook> - sub, runs before approved/declined conditions are checked
+I<hook> - required, sub, runs before approved/declined conditions are checked
-I<approved> - sub, returns true when approved
+I<approved> - required, sub, returns true when approved
-I<declined> - sub, returns true when declined
+I<declined> - required, sub, returns true when declined
I<close_condition> - sub, decide whether or not to close the batch