XML Linking Language (XLink)

World Wide Web Consortium Working Draft 3-March-1998

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Eve Maler (ArborText) <elm@arbortext.com>
Steve DeRose (Inso Corp. and Brown University ) <sderose@eps.inso.com>

Status of this document

This is a W3C Working Draft for review by W3C members and other interested parties. It is a draft document and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use W3C Working Drafts as reference material or to cite them as other than "work in progress". A list of current W3C working drafts can be found at http://www.w3.org/TR.

This work is part of the W3C XML Activity (for current status, see http://www.w3.org/MarkUp/XML/Activity ). For information about the XPointer language which is expected to be used with XLink, see http://www.w3.org/TR/WD-xptr.

See http://www.w3.org/TR/NOTE-xlink-principles for additional background on the design principles informing XLink.


This document specifies constructs that may be inserted into XML resources to describe links between objects. It uses XML syntax to create structures that can describe the simple unidirectional hyperlinks of today's HTML as well as more sophisticated multi-ended and typed links.

XML Linking Language (XLink)

Version 1.0

Table of Contents

1. Introduction
    1.1 Origin and Goals
    1.2 Relationship to Existing Standards
    1.3 Terminology
    1.4 Notation
2. Locator Syntax
3. Link Recognition
4. Linking Elements
    4.1 Information Associated with Links
        4.1.1 Locators
        4.1.2 Link Semantics
        4.1.3 Remote Resource Semantics
        4.1.4 Local Resource Semantics
    4.2 Simple Links
    4.3 Extended Links
5. Extended Link Groups
6. Link Behavior
    6.1 The "Show" Axis
    6.2 The "Actuate" Axis
    6.3 Combinations of the "Show" and "Actuate" Axes
7. Attribute Remapping
8. Conformance


A. Unfinished Work
    A.1 Structured Titles
B. References

1. Introduction

This document specifies constructs that may be inserted into XML resources to describe links between objects. A link, as the term is used here, is an explicit relationship between two or more data objects or portions of data objects. This specification is concerned with the syntax used to assert link existence and describe link characteristics. Implicit (unasserted) relationships, for example that of one word to the next or that of a word in a text to its entry in an on-line dictionary are obviously important, but outside its scope.

Links are asserted by elements contained in XML documents. The simplest case is very like an HTML A link, and has these characteristics:

While this set of characteristics is already very powerful and obviously has proven itself highly useful and effective, each of these assumptions also limits the range of hypertext functionality. The linking model defined here provides ways to create links that go beyond each of these specific characteristics, thus providing features previously available mostly in dedicated hypermedia systems.