U

UPN

See user principal name (UPN).

user

In Active Directory, a security principal (a user who can log on to the domain). A user might have an e- mail address and/or an Exchange mailbox, making the object mail- enabled and/or mailbox-enabled, respectively.

user ban

An action that prevents an individual user from accessing a specific chat community. If a banned user attempts to access a community, he or she is refused. The user can be restricted by nickname, user name, or both.

user principal name (UPN)

A name that is generated for each object, in the form username@domainname. A UPN allows the underlying domain structure and complexity to be hidden from users. For example, although many domains can exist within a forest, users would seamlessly log on as if they were in the same domain.