A reserved DOI can be deleted by sending a DELETE request to the identifier's URL. We emphasize that only reserved identifiers may be deleted; see Identifier status. Authentication is required; only the identifier's owner and certain other users may delete the identifier (see Ownership model).

⇒ DELETE /id/doi:10.5438/test9999 HTTP/1.1
⇒ Host: ez.datacite.org

⇐ HTTP/1.1 200 OK
⇐ Content-Type: text/plain; charset=UTF-8
⇐ Content-Length: 29
⇐ success: doi:/10.5438/test9999

The return is a status line. Assuming success (see Error handling), the remainder of the status line echoes the canonical form of the identifier just deleted.