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:
“John Brown and Giuseppe Garibaldi were contemporaries not solely in the matter of time; their endeavors as liberators link their names where other likeness is absent; and the peaks of their careers were reached almost simultaneously: the Harper’s Ferry Raid occurred in 1859, the raid on Sicily in the following year. Both events, however differing in character, were equally quixotic.”
—John Cournos (1881–1956)
“There is a relation between the hours of our life and the centuries of time. As the air I breathe is drawn from the great repositories of nature, as the light on my book is yielded by a star a hundred millions of miles distant, as the poise of my body depends on the equilibrium of centrifugal and centripetal forces, so the hours should be instructed by the ages and the ages explained by the hours.”
—Ralph Waldo Emerson (1803–1882)