ISO-HTML Structuring Options: ISO/IEC JTC1/SC18/WG8 N1898

[Mirrored from:]

ISO-HTML Structuring Options

International Organization for Standardization
International Electrotechnical Commission


Title:Committee Draft proposal for ISO-HTML
Subject:Structuring options for ISO-HTML
Source:David Abrahamson, Ireland, <> and
Roger Price, France, <>
Project:ISO-Hypertext Markup Language
Status:Proposed Committee Draft
Action:For comment by SC18/WG8 and IETF liaison
by 28th February, 1997
Date:11th February, 1997
Distribution:WG8 and liaisons


The ISO-HTML project requires the development of a formal SGML specification for a fully internationalized ISO HyperText Markup Language based on the W3C Recommendation for HTML 3.2. In addition, the specification should demonstrate the use of currently accepted good SGML practice.

The editors have, wherever possible, conformed to these requirements, however a case has arisen in which a technical decision is required. This informal technical contribution asks SC18/WG8 and IETF liaison experts to comment on the options proposed by the editors.

A question has arisen concerning the degree of logical structuring which should be applied to an ISO-HTML document. Two options are described in this contribution:

  • Simple structuring
  • Full structuring

It should be noted that neither of these options will prevent the rendering of ISO-HTML documents using currently popular browsers.

Document Sections

In this discussion a section is assumed to contain two parts: a heading represented by an <Hx> tag and a body represented by a <Bx> tag. Section elements <Sx> may also be defined which contain matching head and body tags. The simple structuring option uses only the <Hx> and <Bx> elements, whereas the full structuring option uses all three tags.

Simple Structuring

In this option, structure is deduced from the use of <H1>...<H6> tags placed in a document by an author. The DTD requires that the <H1>...<H6> tags be correctly nested, and this can be verified by an SGML validating parser.

Text which follows each <Hx> tag is assumed by the DTD to be enclosed in <Bx> elements which are fully minimizable. The <Bx> and </Bx> tags define the section body.


  • This option does not require an author to use tags that have not been defined in the W3C Recommendation.


  • The end of a section is always implicit: it is defined by the appearance of another <Hx> tag either at the current level or at a containing level.

Full Structuring

In this option, an author explicitly defines a document's logical structure, and is able to define complex structures where a section at level x may include text at a lower level x+1 before continuing again at level x. The author uses <Sx> and (where necessary) </Sx> tags to explicitly specify the start and end of sections. As with the simple structuring option, the <Bx> tags are implicit.


  • This more powerful sectioning mechanism allows for the exact specification of a document's logical structure. This feature would facilitate the future introduction of formal document structuring techniques into browser technology.

  • Legacy HTML documents with correctly nested headers could be converted into the fully structured ISO-HTML form using DSSSL transformations.


  • Authors would be required to use element tags not defined in the W3C Recommendation for HTML 3.2. It is envisaged, however, that these extra tags will be introduced automatically by ISO-HTML conformant authoring systems.

Note: The <DIV> element provides facilities for expressing sectioned document structure. However, the editors believe that it would be better SGML practice to place such functionality within the explicit structured sectioning tags <Sx>. A future version of ISO-HTML might consider removing the <DIV> element in favour of <Sx> elements.

Required Action

The editors request that National Body and IETF liaison experts comment on this matter by posting their preferred option to the mailing list described below (along with the justification for their choice). The editors will incorporate the consensus view of the NB and IETF liaison experts in the CD-proposal text at their next editorial review at the end of February.

Electronic Support

To facilitate comment, an ISO-HTML mailing list has been established for the development of the future ISO-HTML standard.

To join the list, please send an e-mail note to your NB Head of Delegation or to your Liaison representative.

NB HoD's and IETF Liaisons should communicate the names of their HTML experts to the SC18/WG8 Convenor, James Mason <>.

An ftp site is available to NB and IETF liaison experts at <>.

This site provides the following documents:

/isohtml/Question This document
/isohtml/iso-html.dcl SGML declaration

/isohtml/simple Directory of "simple" option
/isohtml/simple/iso-html.ent ISO-HTML entity set
/isohtml/simple/iso-html.dtd ISO-HTML document type definition
/isohtml/simple/sample-no-s.iso-html Sample document

/isohtml/full Directory of "full" option
/isohtml/full/iso-html.ent ISO-HTML entity set
/isohtml/full/iso-html.dtd ISO-HTML document type definition
/isohtml/full/sample-s.iso-html Sample document

End of document.