Self-descriptive messages

In general, the information provided by the RESTful service contains all the information about the resource that the client should be aware of. There is also a possibility of including more information than the resource itself. This information can be included as a link. In HTTP, it is used as the content-type header and the agreement needs to be bilateral—that is, the requestor needs to state the media type that it's waiting for and the receiver must agree about what the media type refers to.

Some examples of media types are listed in the following table: