Type of Link

Identifies the kind of link used with an element. For all elements in this Tag Set that can take links (except the <mml:math> element), this attribute uses the fixed (unchanging) value “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 value of the attribute is the word “simple” and cannot be changed; it is intended for use by software. For the <mml:math> element, the attribute may take any value, but best practice will restrict the value to one defined in the MathML and XLink specifications; see them for further details.

Attribute Values

In Element

Value Meaning
Text, numbers, or special characters A descriptive name for the type of link present, e.g., “simple” for an XML simple (one-ended) link, “extended” for a multi-way link, etc.
Restriction: This attribute may be specified if the element is used.

In Elements

<abbrev>, <award-group>, <bio>, <chem-struct>, <collab>, <conference>, <contrib>, <custom-meta>, <element-citation>, <email>, <ext-link>, <funding-source>, <graphic>, <inline-graphic>, <inline-supplementary-material>, <institution>, <license>, <media>, <mixed-citation>, <named-content>, <nlm-citation>, <product>, <related-article>, <self-uri>, <supplementary-material>, <uri>
Value Meaning
simple The link is an XML simple (one-ended) link. (Although this is one of several valid XLink link types, it is the only value permitted by the default Suite.)
Restriction: This attribute value may not be changed.