DELETE /admin/api/registry/policies/:id

id can be either an actual system id or a string in the format name-version.

Ideally, the delete action should verify proxies possibly using the policy. Maybe include a force parameter to bypass the check.

The check for existing custom policies in use is something to be added both to deletion and update operations, either commanded through the UI or the API. (See THREESCALE-2097). It is outside of the scope of any individual implementation of the API endpoints or UI views