When acquiring continuous data on DARWIN enhanced software DP300-11, the user's manual says that the extension serial number is .YAA (AA is a serial number from 01 to 99), but what happens after 99?

After .Y99, the number changes to .YA1 through 9, then .YB1 through 9, and so on from A to Z. Anything beyond .YZ9 has not been verified.