In HTML these are designated with the rel attribute on link, a, or area elements.
Example uses include the standard way of referencing CSS, , which indicates that the external resource linked to with the href attribute is a stylesheet, so a web browser will generally fetch this file to render the page.
Standardized link relations are one of the foundations of HATEOAS as they allow the user agent to understand the meaning of the available state transitions in a Representational State Transfer system.
The Internet Engineering Task Force (IETF) has a registry of standardized link relations,[3] and a procedure for extending it defined in RFC 5988.
The RDF typed links are fundamental in LOD datasets for identifying the relationship (predicate) type of RDF triples, contributing to the automatic processability of machine-readable statements of the Giant Global Graph on the Semantic Web.