U

UA

(User Agent) A program component that acts on behalf of a messaging user to construct mail messages from user input and to present messages to the user.

UNC

(Universal Naming Convention) A convention for designating paths to files on shared resources, whereby a file is referenced by a string of the format "\\server\sharepoint\…path…\filename.ext".

Unicode

A character-encoding standard that represents most modern writing systems with 16-bit code points. Unicode is a subset of the ISO/IEC 10646-1:1993 standard.

Uniform Resource Locator

See URL.

URI

(Uniform Resource Identifier) An address string referring to an object, typically on the Internet. The most common type of URI is the URL, in which the address maps onto an access algorithm using network protocols. Sometimes URI and URL are used interchangeably. A Uniform Resource Name (URN) is also a URI and identifies a property or resource using a globally unique name. The URI and its syntax is specified in RFCs 1630 and 1808.

URL

(Uniform Resource Locator) A standardized string used to specify a resource on the Internet, such as an HTML document or a disk file. The format of a URL is "protocol://server.network.domain/path/resource" for an HTML document and "file://\\server\sharepoint\path\filename.ext" for a disk file. Sometimes URI and URL are used interchangeably.

URN

(Uniform Resource Name) A standardized Uniform Resource Identifier used to identify a resource irrespective of its network location. The format of a URN normally follows a convention where entities render their properties or resources unique by using a registered domain name in the URN. For example, urn:schemas:mailheader:.

user agent

See UA.

uuencode

(UNIX to UNIX encoded) A UNIX utility for encoding binary data into ASCII, by splitting every three octets into four sextets and offsetting each sextet by 32 decimal.