You should ensure that the names of maps, and names of fields within a mapset (or within multiple mapsets that are copied into one application program) are unique. However, a map can have the same name as a mapset.
Before CICS® can load a physical map, it requires an installed resource definition for the map object. You can either use program autoinstall to create the definition when the mapset is first used, or define a mapset in the CSD using the DEFINE MAPSET resosource definition.
You assemble a BMS mapset definition to generate either a symbolic description map or a physical map. The physical map is a structured data area used at execution time to build the data stream for the terminal. The symbolic map is a series of data structures which you copy into your program at compile time so you can refer to the fields in the map by name.
For programming information about the autoinstall user program, see the CICS Customization Guide.
The DFHMSD macro defines a mapset.
The DFHMDI macro defines a map within the mapset defined by the previous DFHMSD macro. A map contains zero or more fields.
The DFHMDF macro defines a field within a map defined by the previous DFHMDI macro.