CoRE Target Attribute Registry

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Table of Contents

1. Introduction

(Please see abstract.)¶

The original Web Linking specification Section 3 of [RFC5988] did not attempt to coordinate names of target attributes except for providing common target attributes for use in the Link HTTP header. The current revision of that specification clarifies (Section 2.2 of [RFC8288]):¶

This specification does not attempt to coordinate the name of target attributes, their cardinality, or use. Those creating and maintaining serialisations SHOULD coordinate their target attributes to avoid conflicts in semantics or syntax and MAY define their own registries of target attributes.¶

This short note introduces an IANA registry for coordinating names of Target Attributes when used in Constrained RESTful Environments.¶

2. IANA Considerations

This specification defines a new sub-registry for Target Attributes in the CoRE Parameters registry [IANA.core-parameters], with the policy "expert review" (Section 4.5 of [BCP26]).¶

The expert is instructed to be frugal in the allocation of very short target attribute names, keeping them in reverse for applications that are likely to enjoy wide use and can make good use of their shortness. The expert is also instructed to direct the registrant to provide a specification (Section 4.6 of [BCP26]), but can make exceptions, for instance when a specification is not available at the time of registration but is likely forthcoming.¶

Each entry in the registry must include:¶

Attribute Name:

a lower case ASCII [STD90] string that starts with a letter and can contain digits and hyphen-minus characters afterwards ([a-z][-a-z0-9]*). (Note that [RFC8288] requires target attribute names to be interpreted in a case-insensitive way; the restriction to lower case here ensures that they are registered in a predictable form).¶

Brief description:

a brief description¶

Change Controller:

(see Section 2.3 of [BCP26])¶

Reference:

a reference document that provides a description of the target attribute, including the semantics for when the target attribute appears more than once in a link.¶

Initial entries in this sub-registry are as listed in Table 1:¶

A number of names are reserved as they are used for parameters in links other than target attributes, a further set is predefined in [RFC8288].¶

3. Security considerations

The security considerations of [RFC8288] apply, as do those of the discovery specifications [RFC6690], [RFC7252], and [RFC9176].¶

Acknowledgements

TBD¶

Contributors

Jaime provided the list of initial registrations.¶

Author's Address