For system-managed data sets that have not been assigned a management class, DFSMShsm uses the default management class for expiration, migration, and backup information. The default management class does not apply to objects. You specify the name of the management class in the Default Management Class field.

The default management class name is not saved in the data set catalog entry, so that you can tell the difference between data sets with assigned management classes and those without them. Specifying a default management class is optional. If a data set has no management classes and a default management class is not defined, DFSMShsm uses its own defaults for the data set.