ISO/IEC 15445:1999(E)

First edition 1999-00-00

Information technology -- Document Description and Processing Languages -- HyperText Markup Language (HTML)



ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are member of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.

In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75% of the national bodies casting a vote.

International Standard ISO/IEC 15445 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC34, Document description languages. JTC1/SC34 has worked on this project in close cooperation with the World Wide Web Consortium. This International Standard makes normative reference to the W3C Recommendation for HTML 4.0 amended by the HTML 4.0 Specification Errata.

Annexes A and B form a part of this International Standard.


The HyperText Markup Language (HTML) is an application of the International Standard ISO 8879 -- Standard Generalized Markup Language (SGML). It provides a simple way of structuring hypertext documents and of placing references in one document which point to another. This International Standard is a refinement of the World Wide Web Consortium's (W3C's) Recommendation for HTML 4.0; it provides further rules to condition and refine the use of the W3C Recommendation in a way which emphasizes the use of stable and mature features, and represents accepted SGML practice. Documents which conform to this International Standard also conform to the strict DTD provided by the W3C Recommendation for HTML 4.0.

This International Standard makes a clear and important distinction between conforming systems and validating systems. A conforming system operates correctly when handling documents which conform to this International Standard, but is not required to operate correctly when the documents do not conform. A validating system is more powerful; it detects all SGML and HTML errors in a document. Frequently browsers are conforming systems whereas authoring tools check for validity.

This International Standard does not define error handling procedures.

NOTE: International Standard ISO/IEC 15445 assumes that the reader is familiar with International Standard ISO 8879 -- Standard Generalized Markup Language (SGML). Readers who are not experts in SGML may wish to consult the Users Guide to ISO/IEC 15445. The Guide provides more accessible descriptions of the SGML techniques that are used, for example in the document preparation process.

1   Scope

The scope of this International Standard is a conforming application of ISO 8879, SGML. This International Standard describes the way in which the HTML language specified by the following clauses in the W3C Recommendation for HTML 4.0 shall be used, and does so by identifying all the differences between the HTML language specified by the W3C Recommendation for HTML 4.0 and the HTML language defined by this International Standard.

The scope excludes any material in the W3C Recommendation for HTML 4.0 not listed in this clause.