A dummy control section is a reference control section that describes the layout of data in a storage area without reserving any virtual storage.

You might want to describe the format of an area whose storage location is not determined until the program is run. You can do so by describing the format of the area in a dummy section, and using symbols defined in the dummy section in the operands of machine instructions.

The DSECT instruction initiates a dummy control section or indicates its continuation. For more information about the DSECT instruction, see DSECT instruction.