ISO 24751 wiki

Search the space:


Child pages
  • New Version of 24751 Part 1

Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.


Part 1 (Section 5) of this standard provides an abstract model for metadata for this standard. It is based on the Resource Description Framework (W3C …) and interoperable with the Metadata for Learning Resources standard, ISO JTC1 N:19788, and Dublin Core Metadata (ISO N:???).

"RDF has the happy characteristic that "it can say anything about anything." This means that, in principle, any resource can have any property and there is no requirement that any two resources have the same set of properties, even if they have the same type or types. In practice, though, the properties that are set on resources usually follow regular patterns that are dictated by the uses of those resources. Although a particular resource might have arbitrary properties, when viewed from the perspective of a particular application or use case, the set of properties and property values that are appropriate for that resource in that application will often be predictable and constrained. For example, if a server has resources that represent software products and bugs, for the purposes of displaying information in tabular formats, creating and updating resources, or other purposes, a client might want to know what properties software products and bugs have on that server,. The Basic Profile Validation and Constraints specification aims to capture information about those properties and constraints."


By providing for maximum interoperability of AccessForAll metadata, this standard not only caters for accessibility concerns but also makes it easier for general systems to include AccessForAll metadata.

4.5  Support for various levels of granularity
Under some circumstances or user requirements a resource or interface may need to be described at a greater level of specificity than what is already provided in some previous part of the standard. Standards capture the common user requirements. In the implementation of one (or more) Part(s) of
ISO/IEC 24751, however, it is possible that a user may have additional or more precise requirements to be implemented as user extensions or constraints in an Application Profile. This standard shall enable the introduction of “user extensions” by those implementing one or more parts (or combination of parts). The identification of such user extensions and their specification is supported by the overall architecture and structure of ISO/IEC 24751.
Types of user extensions include:

  • the addition of a data element of local value required in addition to those specified in ISO/IEC 24751;
  • the ability to include extra content values for a data element.

A “user extension” that attracts widespread and common use may become a candidate for inclusion and incorporation into ISO/IEC 24751, (e.g., in a new part or later edition).

5 Abstract model

Editors' note: there is a lot to be done here


Figure 2 “Matching Process diagram” illustrates a possible process for matching a digital resource to a user's needs and preferences represented as an UML process diagram.

 6 Specification of


AccessForAll data elements  

6.1 Introduction

A primary principle of this part of ISO/IEC 24751 is that a common set of attributes specifies the essential characteristics of each data element. This clause 6, specification of data elements, defines the attributes of data elements and rules for the values of those attributes.


ISO/IEC 24751-2 AccessForAll Registry conformance is dependent on the function or role played by the conformant technology or application.

ISO/IEC-3 data element conformance depends upon publication data elements.

of free (no-cost) Digital resources are conformant when the metadata record of the digital digital???

IT systems are conformant when they gather and/or process Personal Needs and Preference descriptions as specified in ISO/IEC 24751 to deliver digital resources that match each user's needs and preferences.


Assistive technologies in a specific class are conformant when they respond to the generic elements of ISO/IEC 24751 that apply to that class (e.g., screen readers would respond to screen reader elements). Editors’ note: this notion of ‘generic’ has to be sorted.