The data is either copied from a backup copy of the data set, or from another data set to the target data set.
The data class ACS routine is not invoked, because either the data set already exists, or the characteristics of the data set are derived from the DFSMSdss COPY job.
The storage class ACS routine is invoked to determine whether the data set is system-managed. The copied data might come from a non-system-managed source data set that was then copied to a system-managed target data set.
The management class ACS and storage group ACS routines are invoked only if the data set is system-managed.
See z/OS DFSMSdss Storage Administration for more information on the DFSMSdss COPY command.