Recently, there has been the use of a new acronym in the vocabulary of technical communicators - SGML. SGML, which stands for Standard Generalized Markup Language, is defined as a language for document representation (International Organization for Standardization 1986, p. 1). This standard document markup allows for documents to be reused and shared on a variety of computing platforms.

This article examines the background leading to the development of SGML, advantages of SGML, and difficulties encountered when first using SGML.

Background

With computers being used for text processing, problems arise in handling the text. For example, formats used by different manufacturers are incompatible. Although documents are stored on computers, documents generally have to be converted to another text processing type to be used on a different computer. This conversion entails much time and effort.

Therefore, within the last decade, there has been a focus on document portability. It was recognized that, to access documents on different computers, there had to be standardization. In October 1986, the International Organization for Standardization (ISO) designated a standard for document representation - SGML (International Standard 8879). This standard views documents as files composed of text and structure:

Text (ASCII)

Structure ("tags") (ASCII)

SGML documents are ASCII files. ASCII files can contain uppercase and lowercase letters, numbers, and standard punctuation marks, and each character is assigned a number from 1 to 128. Therefore, SGML documents can be easily exchanged among most computers.

Since its adoption as an ISO standard, many industries are committing to SGML; for example, government agencies, aerospace, computers, telecommunications, and publishing.

Advantages of SGML

Following are just a few of the many advantages of SGML.

Using Special Tag Elements. By using special tag elements within an SGML file, text display can be altered either by the user or by front-end programs to control the text that can be printed or displayed.

Displaying system-specific information. At Unisys Corporation, we use an SGML environment developed within Unisys called Open System for Documentation Engineering (OSDE). Using the capabilities of SGML, we can tag our documentation to indicate platform-specific information using Multiple Variations Methodology (MVM). This is an optional element that we can add to our SGML documents. MVM tags enable writers to designate or tag blocks of text as specific to a hardware or software platform, a user interface, compiler level, or any other difference. One type of MVM tag that we use is the heading checkbox. An example is shown in Figure 1, where: