I believe Peteropny is correct.

The only problem I've ever had was when I gave some to my friend who was not even a Goldpassport member. She tried to make a reservation indicating her intention to use it, depending on availabilty at check-in, and the hotel reservation manager wouldn't enter it into the record. But then she signed up and became a GP member and she had no problem making the reservation and using it at check-in.

I've used them before I became a Diamond. I had no status.