2.1.1.3.3.1 Receivers

The receiver MUST begin the revocation list update procedure by sending a GET_PARAMETER request to the URL that the receiver intends to play or is currently playing. The entity-body of the GET_PARAMETER request MUST contain a revocation list request message.

The GET_PARAMETER request MUST include a "Content-Type: application/vnd.ms-wmdrm-extended-operation-request" header to indicate that the body of the GET_PARAMETER request contains a revocation list request message.

Unlike the registration request and registration response messages, the revocation list request and revocation list response messages MUST NOT be encoded or decoded in Base64 [RFC3548].

When the receiver checks the response to the GET_PARAMETER request. The receiver MUST verify that the response indicates that the request succeeded, and that the response includes the "Content-Type: application/vnd.ms-wmdrm-extended-operation-response" header. The presence of this header indicates that the entity-body of the response contains a revocation list response message.