The "MUF Specific Common Memory Section" of the REPORT MEMORY=MVS report will show all the Multi-Users (MUFs) which had been enabled at some point in time since the last IPL.
A Datacom Shadow MUF which is in waiting mode and has not yet ever been enabled as a MUF will not appear in the report.
A Shadow MUF "waiting" message is:
DB02325I - SHADOW MUF NOW WAITING
A MUF "enabled" message is:
DB00201I - MULTI-USER ENABLED, ...