If you do not want to issue a particular serial number(s) you can set a Do Not Issue flag on the serial number record.


Go to Stock > Serial Numbers and find the serial number in the bottom grid.


Click the Edit button (e to the left of the serial number) and change the flag for the Do Not Issue field to Yes as shown below.



Once the Do Not Issue flag has been set to Yes the serial number will not appear when entering a requisition.