code: public void ip_delegation_target_DELETE(String ip, String target) throws IOException {
  		String qPath = "/ip/{ip}/delegation/{target}";
  		StringBuilder sb = path(qPath, ip, target);
  		exec(qPath, "DELETE", sb.toString(), null);
  	}
docs: Delete a target for reverse delegation on IPv6 subnet
  
  REST: DELETE /ip/{ip}/delegation/{target}
  @param ip [required]
  @param target [required] NS target for delegation