Formatting Output Specification Instance

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In computing, FOSI (Formatting Output Specification Instance) is a stylesheet language for SGML and, later, XML. FOSI was developed by the US Department of Defense to control the pagination and layout of SGML and XML technical data. FOSI stylesheets are themselves written in SGML, an approach that would later be adopted by XSL.

FOSI was implemented by, among others, Datalogics,{{cite book|last=Walsh|first=Norman|title=DocBook: The Definitive Guide, Volume 1|year=1999|publisher=O'Reilly Media, Inc.|isbn=9781565925809|pages=[https://archive.org/details/docbookdefinitiv00wals/page/64 64–65]|url-access=registration|url=https://archive.org/details/docbookdefinitiv00wals/page/64}}{{cite book|last=Von Hagen|first=William|title=SGML for dummies|year=1997|publisher=IDG Books Worldwide|page=[https://archive.org/details/sgmlfordummies00vonh/page/284 284]|isbn=978-0-7645-0175-3 |url=https://archive.org/details/sgmlfordummies00vonh|url-access=registration}} Arbortext{{cite book|last=Wood|first=John M.|title=Desktop Magic: Electronic Publishing, Document Management, and Work Groups|year=1995|publisher=Van Nostrand Reinhold|isbn=9780442017729|page=91}}{{cite book|last=Pawson|first=Dave|title=XSL-FO: Making XML Look Good in Print|url=https://archive.org/details/xslfo00dave|url-access=registration|year=2002|publisher=O'Reilly Media, Inc.|isbn=9780596003555|page=[https://archive.org/details/xslfo00dave/page/184 184]}} and X.Systems. FOSI is documented in the book Practical FOSI for Arbortext Editor (©2015) by Suzanne Napoleon.