Your support for our advertisers helps cover the cost of hosting, research, and maintenance of this FAQ

The XML FAQ — Frequently-Asked Questions about the Extensible Markup Language

Section 1: Basics

Q 1.4: What is SGML?

Standard Generalized Markup Language, ISO 8879:1986

SGML is the Standard Generalized Markup Language (ISO 8879:1986), the international standard for defining markup to describe the structure of different types of electronic document. There is an SGML FAQ from David Megginson at; and Robin Cover's SGML Web pages are at For a brief summary and list of online and print resources, see For a little light relief, try Joe English's ‘Not the SGML FAQ’ at

SGML is very large, powerful, and complex. It was in heavy industrial and commercial use for nearly two decades (and still is, in some places), and there is a significant body of expertise and software that grew up with it, most of which is now available for XML.

XML is a lightweight cut-down version of SGML which keeps enough of its functionality to make it useful but removes all the optional features which made SGML too complex to program for in a Web environment.

ISO standards like SGML are governed by the International Organization for Standardization in Geneva, Switzerland, and voted into or out of existence by representatives from every country's national standards body.

If you have a query about an international standard, you should contact your national standards body for the name of your country's representative on the relevant ISO committee or working group.

If you have a query about your country's representation in Geneva or about the conduct of your national standards body, you should contact the relevant government department in your country, or speak to your public representative.

The representation of countries at the ISO is not a matter for this FAQ. Please do not submit queries to the editor about how or why your country's ISO representatives have or have not voted on a specific standard.