CRC[=AUTODIN_II] Uses the AUTODIN-II polynomial for the 32-bit cyclic redundancy check (CRC) calculation and provides the most reliable end-to-end error detection. This is the default for NRZ/PE (800/1600 bits/inch) tape drives. If you enter only Crc as the qualifier, RMU Backup assumes you are specifying Crc=Autodin_II.