Platform SDK: Exchange Server

U

Unicode
A worldwide character-encoding standard that allows more information to be contained in each string by defining 16-byte character strings rather than the standard 8-byte character strings. Unicode allows universal data exchange and improves multilingual text processing. Unicode strings are also called wide strings. A Unicode string is left-padded with zeroes.
update sequence number (USN)
A property that monitors changes in directory objects as they occur. USNs are used in export operations from a specified server so that only the changed objects will be exported. Only those objects with a USN larger than the largest USN returned during a previous export are exported. USNs are server-specific.
Universal Naming Convention (UNC)
A standard naming convention for applications that enables users to browse documents on the network directly and to open an application's files on remote machines without requiring the user to specify the location of the file on the network or connect to that network. Universal names are location-independent. They also allow users to transfer files to other computers.