This trap is sent when a change occurs in the module structure of a switch. This occurs only when a module is logically removed from or added to a switch. The varBind list contains the updated value of the variable hmSysGroupModuleMap.
Sources for this description
Belden, GarrettCom and Hirschmann IT official standalone MIBsHirschmann MIB copies (LibreNMS/Observium Community)Netdisco MIB archive copies