The externalCrossReference data category encloses a reference to another term, usually a related term (including antonyms and homonyms) that is located in another document. Do not use a formulation such as "Note: See xxx" for a cross-reference to another term. This element will be prepended with the label Related term: in the rendered output.

An externalCrossReference cannot be embedded into a definition or an example. For that purpose, use entailedTerm.

The target attribute is optional for crossReference, and mandatory for externalCrossReference.

This data category is repeatable; you can include as many as you want in an entry.

A crossReference can only occur at the langSet level, whereas an externalCrossReference can occur at either the langSet or the termEntry level.