Glossary -- A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

NDLP Glossary - S

SCORPIO

Subject-Content-Oriented Retriever for Processing Information Online. SCORPIO is a system developed at LC to provide more flexible searching capabilities than MUMS and to support the indexing of full text. SCORPIO was originally developed for the Congressional Research Service, but was adopted widely by staff and end users for reference and retrieval. [MUMS is used primarily for cataloging and other technical processing -- and for searching for specific known items.]

Like MUMS, SCORPIO runs on LC's IBM mainframe. The combination of MUMS and SCORPIO is known as LOCIS (Library of Congress Information System). Users can search for books in the LC collection using either MUMS or SCORPIO commands.

For more details, a handout is available in the Computer Catalog Center across from the main reading room. The handout provides some useful background details and describes the information resources available through SCORPIO and MUMS. Classes for both systems are offered regularly.

SGML

Standard Generalized Markup Language. An international standard (ISO 8879) for coding (marking up, tagging) text documents. Unlike word-processor files, the markup in SGML describes the logical components and structure (rather than the physical layout). Parts of the text might be tagged as paragraphs, headings of various levels, captions, tables, footnotes, etc. If this seems like HTML, it is. HTML is a simple application of SGML. Each SGML document is related to a Document Type Definition (DTD) which defines the information structures allowed in a particular type of document (e.g. a journal article or a book chapter), their permitted relationships, and the tags used to mark them.

For convenience in sharing documents, and to build long-term archives, many DTDs have also been standardized, some through a formal process, others by informal adoption across a particular community. The NDLP is using two particular DTDs. Reproductions of historical texts are coded according to the TEI DTD developed as part of the Text Encoding Initiative. In the future, some collections will be described by finding aids coded according to the EAD (Encoded Archival Description) DTD, which is under development, and for which LC is the maintenance agency.

Before display or printing, a third component is needed, a "stylesheet" that maps the logical tags defined in the DTD into procedural formatting directions. For instance, the style-sheet might indicate that a Helvetica 10 point font be used for regular paragraphs and that the top level of heading should be centered and in 24 point Times. For World Wide Web access, simple stylesheets are integrated into the SGML viewers designed for use with WWW browsers. As of January 1996, free SGML viewers are not available for all computing platforms. Panorama Free for Windows (from SoftQuad) is the SGML viewer in widest use at LC.

The formal title of the standard is ISO 8879 Information processing -- Text and office systems -- Standard Generalized Markup Language (SGML). The first edition was published 1986-10-15, with an amendment published 1988-07-01.

For an introduction to SGML, try A Gentle Introduction to SGML from the Text Encoding Initiative. Another Introduction to SGML for the non-technical is by a Belgian computer scientist.

For MUCH more information about SGML, see

• http://www.sil.org/sgml/sgml.html [Robin Cover maintains this page at the Summer Institute of Linguistics. Included is a list of information about projects at academic institutions.]
• http://www.sq.com/htmlsgml/htmlsgml.htm [SoftQuad, one of the companies developing software tools for creating, managing, and viewing documents in the SGML format.]
• http://www.ebt.com/docs/sgmlinfo.html [Electronic Book Technologies, another SGML-based company.]

The origins of SGML are in IBM in the 1970s. A 1990 history can be found at http://www.sil.org/sgml/sgmlhist0.html.

SGML OPEN is a consortium (mainly of corporations) promoting the use of SGML.

SNA

Systems Network Architecture. IBM's proprietary network architecture, originally developed as a centralized architecture with host computers controlling many terminals.

At LC, SNA is used to link terminals (as opposed to personal computers) to the IBM mainframes. These terminals may be IBM 3270s or emulate the IBM 3270 by using the same protocol. In the past, LC has deployed many terminals from ComTerm and Northern Telecom.

Glossary -- A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
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NDLP Glossary - S -
(4/3/96)