(American Standard Code for Information Interchange) This standard character encoding scheme is used extensively in data transmission.


(American National Standards Institute) This group is the U.S. member organization that belongs to the ISO, the International Organization for Standardization.


An attribute provides more information about an element such as classification level, unique reference identifiers, or formatting information.

CCITT Group 4

(International Consultative Committee on Telegraphy and Telephony) This CALS standard for raster graphics incorporates tiling, which divides a large image into smaller tiles. You can exchange graphic files in CCITT/4 format in a compressed state so they take up much less file space.


(Contractor Integrated Technical Information Service) As part of CALS Phase II, CITIS is a draft functional specification for services. DoD acquisition managers designed CITIS as a plan to gain access to product-related digital technical information.


(Computer Graphics Metafile) CGM is one of the CALS standard formats for representing 2–D technical illustrations. CGM is an object-oriented graphic format.


(Document Style Semantics and Specification Language) This draft international standard (DIS 10179) applies to the specification of processing information for SGML documents. DSSSL is expected to became an international standard.


(Document Type Definition) A DTD is the formal definition of the elements, structures, and rules for marking up a given type of SGML document. You can store a DTD at the beginning of a document or externally in a separate file.


(Electronic Data Interchange) This is a set of computer interchange standards for business documents such as invoices, bills, and purchase orders.


An element is a piece of data within a document that may contain either text or other subelements such as a paragraph, a chapter, and so on.

element declaration

A statement in the DTD defining an element and declaring the order in which it may appear in the document and what other elements it may include.


An entity is a self-contained piece of data that can be referenced as a unit. You can refer to an entity by a symbolic name in the DTD or the document. An entity can be a string of characters, a symbol character (unavailable on a standard keyboard), a separate text file, or a separate graphic file.

entity declaration

A statement in the DTD or document that assigns an SGML name to an entity so you can reference it.


(Formatting Output Specification Instance) A FOSI is used for formatting SGML documents for printing and other outputs. It is a separate file that contains formatting information for each element in a document.


(HyperText Markup Language) This is the format of files published on the World Wide Web. HTML is an application of SGML; to author in HTML using SGML-based authoring software, you simply need the HTML DTD.


(Initial Graphics Exchange Specification) The IGES standard for engineering, product design, and manufacturing drawings is one of the CALS standard graphics formats.


The Internet is a worldwide communications network originally developed by the U.S. Department of Defense as a distributed system with no single point of failure. The Internet has seen an explosion in commercial use since the development of easy-to-use software for accessing the Internet.


(International Organization for Standardization) The ISO is an industry-supported organization that establishes worldwide standards for everything from data interchange formats to film speed specifications.


Markup is anything added to the content of the document that describes the text.


A parser is a specialized software program that recognizes SGML markup in a document. A parser that reads a DTD and checks and reports on markup errors is a validating SGML parser. A parser can be built into an SGML editor to prevent incorrect tagging and to check whether a document contains all the required elements.


(Product Data Exchange Standard/Standard for the Exchange of Product Model Data). PDES/STEP are standards under development for communicating a complete product model with sufficient information content that advanced CAD/CAM applications can interpret. PDES is under development as a national standard and STEP is under development as its international counterpart.


In the world of SGML, a tag is a marker embedded in a document that indicates the purpose or function of the element. Each element has a beginning tag and an end tag.

World Wide Web

Often referred to as WWW or the Web, this usually refers to information available on the Internet that can be easily accessed with software usually called a "browser." Organizations publish their information on the Web in a format known as HTML; this information is usually referred to as their "home page" or "web site".