Things seen in a distant past
Reminds me of a gig I did as a contractor in the mid 1970's. Client company was running a small IBM mainframe (370/135?) with removable disks.
To make things 'easier' for everyone (operations and programming staff) TPTB decided the production and test disk packs would have the same volume serial numbers.
They did until the day the production disks were overwritten during a test run.