Input data descriptor FM header
On input to IMS, this header can follow the ATTACH or SCHEDULER FM header and is used to receive a data structure name (if DPAGE selection is by DPAGE name) and version ID or the input field tab separator character.
The input data descriptor FM header should be sent to IMS if input DPAGE selection is to be performed on the DPAGE name; that is, if you specify OPTIONS=DNM on the DIV statement (TYPE=INPUT).
If you set OPTIONS=DNM, and specify no DPAGE name or the wrong DPAGE name, an error occurs.
The version ID should be sent to IMS in the first or only FM header of the input message if MFS is to verify that the correct definition is used to map the data. If the version ID is sent and is X'0000', no verification occurs. The field tab separator is not required on input, because MFS provides for up to eight separators with the FTAB function. If received on input, the field tab separator is used instead of the MFS FTAB specification (if any) for the current transmission.