The SYSIN DD statement is optional. If it is omitted, or a DUMMY data set, or an empty data set, IEBCOPY will generate a control statement using options in the PARM field.

SYSIN will not be opened if COPY, COPYMOD, REPLACE, or COMPRESS appears in the PARM field.

If you are copying, loading, or unloading a single data set, or wish to compress a data set in place, you can avoid using utility control statements by using SYSUT1 for the input data set and SYSUT2 for the output data set.

Either fixed, variable, or undefined record format is acceptable, as is any BLKSIZE and LRECL consistent with the record format and each other. If the record format indicates carriage controls, the carriage control character in each record is ignored.

Sequence numbers are optional. IEBCOPY will look for sequence numbers (8 digits long) at the front of variable format records and at the end of fixed format records. If IEBCOPY finds them in the first control statement, it will ignore those columns in all control statements.

Related reading: For more information, see Avoiding the Need to Supply Control Statements .