mapgroupname
The name of the generated mapgroup. The mapgroup must have the filetype (VM/CMS) or ddname (MVS) of ADMGGMAP. This is the filetype or ddname generated by GDDM-IMD. If mapgroupname ends with two dots, GDDM will supply the last two characters, which indicate the device class.

mapname
The name of the map.

prefix
The prefix used for the associated REXX variables. To ensure that REXX mapping variables have unique names, specify each prefix with an underscore (_) at the end.