Standard Generalised Markup Language. The international standard (ISO) for specifying the structure and content of electronic documents, and identifying elements in a text document which can interpreted by other markup languages—e.g., HTML, XML, DHTML.
* Metamarkup, which provides the ability to control the definition and interpretation of markup tags, and to extend the vocabulary of derivative markup languages. Metadata, the concept of information about information, is related to this concept, if you would like to read the Coombs, Renear, and DeRose paper that the preceding definitions were taken from, you can find it online at www.oasis-open.org/cover/coombs.html#Figure1.
A groundswell in the library community moved to explore how SGML (Standard Generalized Markup Language) conformant records could be used for content designation of document types beyond bibliographic records and to find relationships between the SGML and MARC bibliographic records in library catalogs.