You can code comments by placing an asterisk (*) in column 1 of your SYSIN.
InformationExample
//SYSIN    DD * 
* Copy production table space
 COPY TABLESPACE ACPDBSMP.ACPTS001 
 COPYDDN(LOCALP,LOCALB) 
 RECOVERYDDN(RECOVRP,RECOVRB) 
 FULL YES
//SYSIN    DD * 
* ANALYZE YES reports results without deletion
MODIFY RECOVERY TABLESPACE ACPDBSMP.ACPTS001 
DELETE    WHERE START_RBA < X'0003732E40AF' 
ICFDELETE YES 
ANALYZE YES
 You can also code comments by preceding information with a double hyphen (--). A comment starts with the hyphens and runs to the end of the line. You can place the double hyphen in column 1 through column 70, but you cannot break it across lines.
InformationExample
//SYSIN    DD * 
-- Copy production table space
 COPY TABLESPACE ACPDBSMP.ACPTS001 
 COPYDDN(LOCALP,LOCALB) 
 RECOVERYDDN(RECOVRP,RECOVRB) 
 FULL YES
//SYSIN    DD * 
-- ANALYZE YES reports results without deletion
MODIFY RECOVERY TABLESPACE ACPDBSMP.ACPTS001 
 DELETE    WHERE START_RBA < X'0003732E40AF' 
 ICFDELETE YES 
 ANALYZE YES
All characters on the line following the comment designation, both those specified with an asterisk in column 1 and those specified with a double hyphen, are ignored.