If sysno is provided, then it's used to identify the reocord.
If not, and match_criteria is provided, then sysno is guessed
If not, and a record is provided, then sysno is got from there
If sysno is provided, then it's used to identify the reocord.
If not, and match_criteria is provided, then sysno is guessed
If not, and a record is provided, then sysno is got from there