Spam Up
I think I understand what you are after. I have been to many airports where the lack of a crew ID means a painfull diversion all over the airport to get to the aircraft, also, sometimes difficulty in obtaining crew visa's. If you are with a company produce your own in house, if you are freelance produce your own with your trading name, the best is to get an airport pass from your base airport. They all work just fine, shows just what a load of bxxxxx it all is. I confess I do not know what an ICAO approved ID badge is.