1.4 Relationship to Other Protocols
This document defines version 1.0, version 2.0, and version 3.0 of the OData protocol, which is based on the AtomPub [RFC5023] specification, which, in turn, relies on HTTP [RFC2616]. Either HTTP 1.1 or HTTP 1.0 may be used with the OData protocol. The OData protocol uses HTTP headers that are defined in the HTTP specification, but are not referenced in the AtomPub specification.
Figure 1: OData Relationship to Other Protocols