The Web Annotation Vocabulary provides the terms and definitions which underpin the related Web Annotation Data Model. The terminology (and specifications) can make the underlying concepts seem a bit obtuse, but fundamentally a Web Annotation is a (typically purposeful) object which has a target and associates it with zero or more bodies. If you can get past all the language, this is fundamentally a very simple model which is broadly applicable.

This ontology does not define every term in the Web Annotation Vocabulary, but it does define most of them. Terms it excludes include :⁠—

, as it merely offers a discovery endpoint for the Web Annotation Protocol, which this ontology makes no claims to support.

, as it defines what is in essence a rendering detail. If two bodies are, for example, equivalent but in different languages, it would be better to provide that information via relationships between the bodies themselves, and leave it to renderers to determine whether to display both or choose between them.

, , , and , as these are rendering details which ought to be left to applications.

is underspecified, and its value is generally described as a string, not the more appropriate .

follows an undesirable pattern of recommending a plaintext string value, with its language and media type specified thru other properties. For plaintext strings, it is better for language to be provided via the mechanism, and it is better that X·M·L values be provided as s. Because these things complicate the processing model and it is unlikely that existing Web Annotation tools would support them, this ontology chose not to complicate . Instead, should be used.

, for the same reasons as .

is semantically muddled; Time States don¦t generally have sources, so how can they have cached ones? This would have been better modelled as a property of the enclosing Resource Selection.

, while providing interesting and potentially meaningful provenance information, adds additional complexity to the model without any known practical use·cases. This ontology may choose to define it at a later time if practical use·cases are found.

Properties originally defined by other vocabularies, when those vocabularies are not otherwise defined in this ontology.