How to call out gold TiN coating

I'm calling out a TiN coating to match a previous product which was done by a company which is now closed. The drawing call for TiN coating, gold and nothing else. What is the proper way to call out the TiN coating of a part on a drawing?
Thanks in advance.

The specification of the coating should depend on the application. If it's primary deposited for improved wear resistance, you should specify a thickness of 3 to 5 microns. The deposition process may also make a difference. Most PVD processes are carried out with substrate temperatures around 450 &C, and wind up with a coating having high compressive stress. TiN can also be deposited by CVD at around 1200 &C, winding up with a low tensile stress.

The only industrial specification I am aware of is AMS2444, which covers PVD TiN coatings. Acceptance tests are for thickness, adhesion, and 'quality' (color, coverage, freedom from nodules). Periodic tests include coating composition, hardness, and microstructure. It's probably getting a copy from SAE ($47.20 at www.sae.org) as a model for your own purchase document, if for no other reason.