When BRBACKUP or BRARCHIVE requests a scratch volume for backup, this means that you can use any volume for which the expiration period has ended. It does not mean that you have to mount a volume with the name SCRATCH .
You can also initialize a volume with the name SCRATCH explicitly, for example, using brbackup -i -v SCRATCH . Such a volume is always accepted, even when a volume with another name is requested. The program still makes sure that the expiration period has expired. In this case the tape mounted is assigned the name of the requested tape. Only use this option in exceptional cases, for example, when an additional tape is requested unexpectedly during a backup operation.
A backup on a tape named SCRATCH should never exist. However, this situation might occur when a scratch tape is requested and a tape named SCRATCH is mounted.