SGML and FOSI Structure: An Overview
All SGML documents must conform to certain rules that are defined partially by the standard and partially by a prolog to the document, which is called the document type definition (DTD).
In addition to being first off the starting blocks to becoming a recogized standard, the FOSI is also the most manageable.
Figure 1. Typeset Document Fragment.
provides data on a different aspect of the formatted output. There are 24 categories (with names such as font, leading, etc.), and each of these has from one to 13 attributes. These. when fully specified, exactly define the formatting aspect with which their category is concerned. These attributes are
characteristics, of Once values for
which all the
there are 128 characteristics
in of be on
The categories control the font, leading, hy- phenation, word spacing, letter spacing, indents. horizontal justification, highlight. change marks, prespace, postspace, page breaking, vertical justifi- cation, text breaking, spanning, page borders, rul- ing, character fill, enumeration, print suppression. automatic generation of text, automatic generation of graphics, the saving of text for cross reference, and the use of text saved for cross reference.
As mentioned above, the elements that may appear in a styldesc are docdesc, envdesc, and e-i-c. The characteristics of the docdesc define the style of the overall document and specify the default values for characteristics that are needed but not specified in an e-i-c. When used in this way, the docdesc is called the default environment. The envdesc section defines "named" environments that may be used instead of the default environment. The actual style definition for an element in a particular context in the document instance is given by an e-i-c. The SGML terminology for an element's name is the generic identifier (gi). An e-i-c specifies an element, its context, and its occurrence within that context
TUGboat, Volume 12 (1991), No. 3-Proceedings
Typesetting SGML Documents Using
by using the gi. context, and occur attributes, as shown in Listing 2.
Furthermore, this FOSI also uses the occur at- tribute of an e-i-c to make a distinction between the output format of the first and non-first occurrences of the para element. The paragraph indent of the
first para within a structure is zero, while
paragraphs have an additional prespace
indent of 15 points
the formatted output from
non-first and an 1 shows instance listed in
the e-i-c definitions in the docdesc (not
default to shown).
As with most SGML documents, the FOSI must first be read by an SGML parser or a dedicated program, and then translated into a form suitable for the formatting engine. Likewise, the document instance
of the 1991 Annual Meeting