Links to other resources often need to be represented in responses. There is already a well established format for this representation in JSON Hyper-Schema: Hypertext definitions for JSON Schema. This is already the prevailing representation in use by a number of prominent OpenStack projects and also in use by the Errors guideline.
Note
Before inventing a new value for rel, please check the existing Link Relations for something you can reuse.
{ "links": [ { "rel": "help", "href": "http://developer.openstack.org/api-ref/compute/#create-server" } ] }