I did not cover the parts of the SGML declaration in the order they
occur in the declaration. I covered them in roughly the order of
their importance and/or frequency of use. For the correct order of
the sections and a complete example of an SGML declaration, consult
the following example.
I also have not introduced the syntax for introducing the SGML
<!SGML "ISO 8879:1986" ... >
where the ellipsis represents the body of the SGML declaration.
This literal string identifies the level of SGML that you used when
creating the document. At this time there is only one level but in
the future (ISO standards are reviewed and possibly revised on a
five year cycle) it is possible that a new revision of the SGML
standard will be released. Don't be concerned about this; it is a
fundamental criteria for the designers working on the revision that
no current documents will be rendered invalid by any changes made
(if any are indeed made).
Notice the : in this literal. This is a change to the
original SGML standard in the first (and only) amendment. In the
original SGML standard that was issued in 1986, this character was
a -. Occasionally, you will encounter systems that have not
changed their code to reflect this change in the standard.
Wayne L. Wohler,
Publishing Solutions Development,
PO Box 1900,
Boulder, Colorado 80301-9191