A VOB that has both attributes stores UCM project metadata and UCM components; a VOB that has neither attribute is an ordinary VOB. Ordinary VOBs and UCM component VOBs are permanent repositories for versioned artifacts. They account for the bulk of the VOBs in any Rational® ClearCase® community.
Any VOB can also be part of an administrative VOB hierarchy. For more information about administrative VOB hierarchies, see VOB datatypes and administrative VOB hierarchies.
In a small Rational ClearCase community, a single VOB can be an administrative VOB, a PVOB, and either an ordinary or a UCM component VOB. It is far more common for a community to require one or more administrative VOBs and a number of ordinary VOBs or, if UCM is in use, a PVOB and a number of component VOBs. Larger communities might require multiple administrative VOBs or PVOBs.