The following DD statements may be required:
- SYSTSIN
 
- For the data set that contains input to the REXX exec. It can be an instream data set.
 
- SYSTSPRT
 
- For the data set that contains output from the exec.
 
- SYSEXEC
 
- SYSPROC
 
- If the exec is a member of a PDS.
 
You must also include any DD statements for data sets that are accessed by the exec.