Hello Ipman, I work a lot with an enterprise company which they create multiple barcode patterns for their forgeign media pools. They have multiple libraries with many differnt media types (LTO2,3,4) and barcode schemes. They manage this by creating patterns for all possibilities and setting these barcode patterns on their foreign pools. They apply the barcode patterns on the foreign pools they do not wish to be part of their default scratch pool. They still use the default scratch for assignment to their storage policy copies.
To provide you an example I have provided a screenshot of properties of an example Barcodes Pattern config in control panel and of a foreign pool.
CommVault, Business Critical Support