WordNet (r) 3.0 (2006):

standard generalized markup language
    n 1: (computer science) a standardized language for the
         descriptive markup of documents; a set of rules for using
         whatever markup vocabulary is adopted [syn: standard
         generalized markup language, SGML]

The Free On-line Dictionary of Computing (30 December 2018):

Standard Generalized Markup Language
SGML

    (SGML) A generic markup language for
   representing documents.  SGML is an International Standard
   that describes the relationship between a document's content
   and its structure.  SGML allows document-based information to
   be shared and re-used across applications and computer
   platforms in an open, vendor-neutral format.  SGML is
   sometimes compared to SQL, in that it enables companies to
   structure information in documents in an open fashion, so that
   it can be accessed or re-used by any SGML-aware application
   across multiple platforms.

   SGML is defined in "ISO 8879:1986 Information processing --
   Text and office systems -- Standard Generalized Markup
   Language (SGML)", an ISO standard produced by JTC 1/SC 18
   and amended by "Amendment 1:1988".

   Unlike other common document file formats that represent both
   content and presentation, SGML represents a document's content
   data and structure (interrelationships among the data).
   Removing the presentation from content establishes a neutral
   format.  SGML documents and the information in them can easily
   be re-used by publishing and non-publishing applications.

   SGML identifies document elements such as titles, paragraphs,
   tables, and chapters as distinct objects, allowing users to
   define the relationships between the objects for structuring
   data in documents.  The relationships between document
   elements are defined in a Document Type Definition (DTD).
   This is roughly analogous to a collection of field
   definitions in a database.  Once a document is converted
   into SGML and the information has been 'tagged', it becomes a
   database-like document.  It can be searched, printed or even
   programmatically manipulated by SGML-aware applications.

   Companies are moving their documents into SGML for several
   reasons:

   Reuse - separation of content from presentation facilitates
   multiple delivery formats like CD-ROM and electronic
   publishing.

   Portability - SGML is an international, platform-independent,
   standard based on ASCII text, so companies can safely store
   their documents in SGML without being tied to any one vendor.

   Interchange - SGML is a core data standard that enables
   SGML-aware applications to inter-operate and share data
   seamlessly.

   A central SGML document store can feed multiple processes in a
   company, so managing and updating information is greatly
   simplified.  For example, when an aeroplane is delivered to a
   customer, it comes with thousands of pages of documentation.
   Distributing these on paper is expensive, so companies are
   investigating publishing on CD-ROM.  If a maintenance person
   needs a guide for adjusting a plane's flight surfaces, a
   viewing tool automatically assembles the relevant information
   from the document repository as a complete document.  SGML
   can be used to define attributes to information stored in
   documents such as security levels.

   There are few clear leaders in the SGML industry which, in
   1993, was estimated to be worth US $520 million and is
   projected to grow to over US $1.46 billion by 1998.

   A wide variety tools can be used to create SGML systems.  The
   SGML industry can be separated into the following categories:

   Mainstream Authoring consists of the key word processing
   vendors like Lotus, WordPerfect and Microsoft.

   SGML Editing and Publishing includes traditional SGML
   authoring tools like ArborText, Interleaf, FrameBuilder
   and SoftQuad Author/Editor.

   SGML Conversions is one of the largest sectors in the market
   today because many companies are converting legacy data from
   mainframes, or documents created with mainstream word
   processors, into SGML.

   Electronic Delivery is widely regarded as the most compelling
   reason companies are moving to SGML.  Electronic delivery
   enables users to retrieve information on-line using an
   intelligent document viewer.

   Document Management may one day drive a major part of the
   overall SGML industry.

   SGML Document Repositories is one of the cornerstone
   technologies that will affect the progress of SGML as a data
   standard.

   Since 1998, almost all development in SGML has been focussed
   on XML - a simple (and therefore easier to understand and
   implement) subset of SGML.

   "ISO 8879:1986//ENTITIES Added Latin 1//EN"
   (http://ucc.ie/info/net/isolat1.html) defines some
   characters.  [How are these related to ISO 8859-1?].

   ISO catalogue entry (http://iso.ch/cate/d16387.html).

   SGML parsers are available from
   VU, NL (ftp://star.cs.vu.nl/Sgml),
   FSU (ftp://mailer.cc.fsu.edu/pub/sgml),
   UIO, Norway (ftp://ifi.uio.no/pub/SGML/SGMLS).

   See also sgmls.

   Usenet newsgroup: news:comp.text.sgml.

   ["The SGML Handbook", Charles F. Goldfarb, Clarendon Press,
   1991, ISBN 0198537379.  (Full text of the ISO standard plus
   extensive commentary and cross-referencing.  Somewhat cheaper
   than the ISO document)].

   ["SGML - The User's Guide to ISO 8879", J.M. Smith et al,
   Ellis Harwood, 1988].

   [Example of some SGML?]

   (2000-05-31)