Type of Link

The kind of link used with an element. For all elements in this Tag Suite that can take links (except the <mml:math> element), this attribute may be either omitted or set to the word “simple”, which means that the link is a simple, one-ended link. For the <mml:math> element, the attribute may take any value that describes the link type, for example, a “simple” (one-ended) link, a “locator” link, a “title” link, an “extended” (multi-way) link, etc.


For all elements (except <mml:math>), the only valid value for the attribute is the word “simple”, but the attribute is optional and may be omitted. For the <mml:math> element, the attribute best practice will restrict the value to one defined in the MathML and XLink specifications; see them for further details.

Attribute Values

In Element

Text, numbers, or special charactersA descriptive name for the type of link present, for example, “simple” for an XML simple (one-ended) link, “extended” for a multi-way link, etc.
Restriction: This is an optional attribute; there is no default.

In Elements

<abbrev>, <award-group>, <award-id>, <bio>, <chem-struct>, <collab>, <conference>, <contrib>, <custom-meta>, <element-citation>, <email>, <ext-link>, <funding-source>, <funding-statement>, <graphic>, <inline-graphic>, <inline-supplementary-material>, <institution>, <license>, <long-desc>, <media>, <mixed-citation>, <named-content>, <nlm-citation>, <product>, <related-article>, <related-object>, <self-uri>, <supplementary-material>, <uri>
simpleThe link is an XML simple (one-ended) link.
Restriction: This is an optional attribute, but if used, is restricted to the word “simple”.