Message Requirements

B 042	An IDS Meta Data Broker must announce the supported IDS Information Model versions for outbound and inbound messages through its Self-Description document.
B043	Both categories from B13 are based on request and response messages: a) Instance of an Request or Notification Message (from Connector to an IDS Meta Data Broker) and an according Response instance (including a possible Rejection Message) (from an IDS Meta Data Broker to a Connector) b) QueryMessage (from a Connector to an IDS Meta Data Broker) and an according ResultMessage or suitable RejectionMessage.
B 044 (B15)	Every Message contains a unique messageId (URI). The corresponding ResponseMessages must contain this messageId as a correlationMessage attribute.
B 045 (B16)	A DescriptionRequestMessage sent to An IDS Meta Data Broker targets at most one of the following IDS entities identified by an URI: a) Connector b) Resource If not provided with an URI a DescriptionRequestMessage has to be interpreted as a Request of a Self Description of the Broker.
B 046 (B21)	A QueryMessage send to An IDS Meta Data Broker contains exactly one action: a) Query (one or multiple meta datasets by a query expression)
B 047	An IDS Meta Data Broker must reject messages if they do not conform to the IDS Information Model specifications and should send a proper RejectionMessage in that case.
B 048	If an IDS Meta Data Broker accepts a registration attempt, it must acknowledge it using a MessageProcessedNotification. A MessageProcessedNotification must not be sent if the indexing led to an error.
B 049	Error Handling: An IDS Meta Data Broker must react with Rejection Messages and appropriate error messages as follows: - Message syntax is wrong: idsc:MALFORMED_MESSAGE (for instance: incorrect JSON-LD, incorrect Multipart) - Security Token or other identity or security related claims are wrong/could not be verified: idsc:NOT_AUTHENTICATEDincluding a hint to the first corrupted attribute causing the rejection (e.g. "Invalid DAT." or "DAT attribute does not match requesting hostname.") - Access not granted because any requirement was not met: idsc:NOT_AUTHORIZED including a hint to the first corrupted attribute causing the rejection. - Requested resource does not exist or requester has no permission to this specific resource: idsc:NOT_FOUND - Message Type is not supported: idsc:MESSAGE_TYPE_NOT_SUPPORTED (e.g. for an ParticipantRegisterMsg to an IDS Broker). - Header or Payload use an Information Model version which the Connector can not handle: idsc:VERSION_NOT_SUPPORTED with a list of supported versions. - The Broker faced an unexpected internal error:idsc:INTERNAL_RECIPIENT_ERROR with contact details of the responsible operator. Additional requirements may be specified in the respective Information Model.