directory management domain (X.500) (DMD)
The Directory Management Domain (DMD) of X.500 is a management domain( MD) in a directory service. Such a domain consists of one or more Directory User Agents( DUA) managed by a single organization.
If a Directory Management Domain is a public service domain, then it is an Administrative Management Domain( ADMD), if it is a private domain, then it is a Private Management Domain( PRMD).