Creation date/time of the content
Authenticated identifier of the creator of or authority for execution of a message
A unique identifier created by the Producer and copied by Consumer into all Responses, in order to support reference to a particular Command, transaction, or event chain
Authenticated identifier(s) of the authorized recipient(s) of a message
Media Type that identifies the format of the content, including major version. Incompatible content formats must have different content_types. Content_type application/openc2 identifies content defined by OpenC2 language specification versions 1.x, i.e., all versions that are compatible with version 1.0.