Web Annotation Protocol
Web Annotation Protocol is a W3C recommendation for servers providing notes or annotations related to particular web pages. It defines a format based on JSON serialization and some rules regarding the requests and responses pertaining to this format.
The full content type (MIME type) line when this data is served is
application/ld+json;profile="http://www.w3.org/ns/anno.jsonld", including a 'profile' parameter.