You can specify various member name for the copy operation.
If you specify TOMBR (*FIRST), the copy operation does not specify a label identifier. Therefore, you must specify a label identifier (LABEL parameter) on an OVRTAPF command. If you specify the special value *FIRST, or *TAPF on the copy command, then the copy command uses the label from the device file description.
If the from-file is tape, the copy command uses the from-file label as the label for a tape to-file. If the to-file is a database file, the command uses the nonblank characters to the extreme right of the from-file label for the member name of the to-file. The command uses up to a maximum of either 10 characters or to the period at the extreme right in the from-file label. The copy operation uses only valid member names for a database to-file.
If the from-file is a tape file that is not labeled, then a to-file member or label name is created that corresponds to the data file on the tape from-file in the form of CPYnnnnn, where nnnnn is the tape sequence number of the data file.