Type of Content


Identification of the subject or type of content contained in an annotation. As an example, this attribute could be used to indicate that annotation material has been added to explain a past medical practice, such as hydrotherapy, mentioned in the original text. Similarly, this attribute could be used to mark that an annotation provided commentary on the material, or to say that the annotation was penciled marginalia in the printed work.


The <annotation> element usually causes the word or phrase identified to be treated in a special way, for example, given a different look in print or on display. This formatting may be guided by the content-type attribute, for example, making all annotations which provide commentary red.

Attribute Values

In Element

<annotation> Annotation
Value Meaning
Text, numbers, or special characters Names/describes the subject or type of content for an <annotation>. For example, this attribute might use the value “commentary” to indicate that an annotation provided commentary, or use the value “definition” to denote an explanation of a medical practice.
Restriction: This attribute may be specified if the element is used.