We call all patrons to let them know what the issue is. We do not clear the item from the record. Usually, the items go on a shelf in DB order for ease of matching up the other halves. We also put a note in the patron's comments.
The administrator has disabled public write access.
Sorry this is a little long.
In South Carolina, we return all mismatched or missing cartridges and containers to patrons with this note inside (attached). It is printed on bright yellow paper.
We go on the assumption that the matching cartridges and containers are at the patron's home.
A note is made on a spreadsheet of the patron's name and ID; book numbers of the mismatched cartridge or container; and the date received and sent back. Only one staff member actually handles the issue.
If the patron calls asking about the note or why the container was returned to them we explain what has happened and that our policy is to send them back to the patron to be matched up.
If the patron claims they were both sent back already or that they cannot match them up, we'll usually mark both NAC/LUN in the catalog and notify the staff member to be on the lookout for those two.
If they are sent back a second time still mismatched, a second note is made on the spreadsheet, and the cartridge and container go to a set aside area (separately).
Every week the assigned staff member checks to see if a match can be made from the mismatched ones. If so then they are checked in. Otherwise they stay on the patron's record. They may be marked lost by a Readers Advisor at some point in the future if a significant amount of time has passed.