What is the best way to process Credit invoices in Payables?

PeopleSoft Version 9.2, Image 40, PeopleTools 8.57

Our AP processes a credit memo with a Regular voucher as a credit amount. This doesn't link the original voucher to the credit in any way and leaves both vouchers as an open liability, even though at times they may zero one another out.

I've tested using an Adjustment voucher and linking the original voucher number to it, but this still leaves the original voucher as an open liability.

How do other organizations process credit memos in the Payables module?

Do you have specific queries that identify Open Liabilities or do you use a canned report?