3.4.5.3.1 Common Rules for Responses to RTSP Requests
The following rules apply for all RTSP responses sent by the DMS, unless specified otherwise.
The response MUST include the headers required by [DLNA] guideline 7.4.210.
The response MAY include the Supported header, as specified in section 2.2.3.3.2, except in the case of a DESCRIBE request, in which case the response SHOULD include the header.
The response MAY include the X-Playlist-Gen-Id header, as specified in section 2.2.3.7, except in the case of a DESCRIBE request, in which case the response SHOULD include the header.