X.400

A set of internationally-agreed recommendations (defined by the CCITT) describing a standard approach to building messaging systems which can be used to carry e-mail, EDI, fax and a range of other data. X.400 boasts a number of features not available on Internet mail systems, including notifications confirming the delivery of messages and security.

X.500

Comparable to an electronic yellow pages where a wide variety of data can be stored, including names, e-mail and postal addresses, telephone numbers, even photos and video clips. Information on machines and the routing of e-mail can also be stored here and used by a message handling system. X.500 is also a series of internationally agreed standards detailing how to build such a directory. It is most frequently used as a corporate address book, but has the potential to become a global source of information. Technically, the CCITT directory standard for X.400 and X.435.

XCK

Destroyed Check Entry. An ACH format used to clear and settle items that originate as checks, but the original paper item was lost or destroyed due to catastrophic event (e.g., an airplane crash) and now the item is being cleared as an ACH transaction.

XI2 STANDARDS

The XI2 standards are generic EDI standards designed to allow a company to exchange data with any other company, regardless of industry. The standards are maintained by the Accredited Standards Committee XI2 (ASC XI2), with the American National Standards Institute (ANSI) accredited to set standards for EDI. The X12 standards are often called the ANSI XI2 standards.

XML

Extensible Markup Language. Souped-up version of the Internet language behind web pages. This is designed to be open and ubiquitous, unlike the code that supports EDI.

X-TERM

An X-windows client that provides a window for terminal emulation.