2.1.9 Section 4.5.1 Annotation odata.context
The specification states the following:
The odata.context annotation returns the context URL (see [OData-Protocol]) for the payload. This URL can be absolute or relative.
OData in the specified Microsoft implementations (section 1.3) partially supports this feature. The name of the odata.context annotation is "odata.metadata" and is written without the leading "@". The contents of the odata.metadata annotation differs from that of the odata.context annotation prescribed in [OData4.0-1Protocol] as described below in sections 184.108.40.206 through 220.127.116.11.
Section 4.5.1 of the specification also states the following:
The odata.context annotation MUST also be included for entities whose entity set cannot be determined from the context URL of the collection.
OData in the specified Microsoft implementations (section 1.3) does not support this feature. Entity sets can always be determined from the metadata URL of the collection and MUST NOT be present for individual entities within a collection or collections within an entity.