A link relation is a descriptive attribute attached to a hyperlink in order to define the type of the link, or the relationship between the source and destination resources. The attribute can be used by automated systems, or can be presented to a user in a different way.
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. Another example is rel="shortcut icon" for the popular favicon icon.
Link relations are used in some microformats (e.g. rel="tag" for tagging), in XHTML Friends Network (XFN), and in the Atom standard, in XLink, as well as in HTML. 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 REST system.
The Internet Engineering Task Force (IETF) has a registry of standardized link relations, and a procedure for extending it defined in RFC 5988. HTML 5 also defines valid link relations.
Read more about Link Relation: Rev Attribute
Famous quotes containing the words link and/or relation:
“All successful men have agreed in one thing,—they were causationists. They believed that things went not by luck, but by law; that there was not a weak or a cracked link in the chain that joins the first and last of things.”
—Ralph Waldo Emerson (1803–1882)
“Much poetry seems to be aware of its situation in time and of its relation to the metronome, the clock, and the calendar. ... The season or month is there to be felt; the day is there to be seized. Poems beginning “When” are much more numerous than those beginning “Where” of “If.” As the meter is running, the recurrent message tapped out by the passing of measured time is mortality.”
—William Harmon (b. 1938)