The SGML Standard Identification:
SGML has many features not described in this document. For further details, see the standard, [iso8879] or [goldfarb] (better, since it contains all the standard text plus commentary).An SGML Application Conforming to International Standard ISO 8879 - Standard Generalized Markup Language
The HyTime Standard Identification:
For further details of the possibilities available via HyTime, see Appendix E.1.2, or the HyTime standard, [iso10744].A HyTime application conforming to International Standard ISO/IEC 10744 - Hypermedia/Time-based Structuring Language