As long as there's any amount of leeway in enforcement of the law, things like courtesy cards will exist. All it is is a little nudge to say, "Hey. I'm one of you and yours. Let's let it slide."
That will continue to exist even if the cards entirely disappear.
The moment it’s standardised not only in writing, but as a physical object, it should become trivially prosecutable. The existence of these cards should trigger DoJ intervention. (Maybe the Adams administration’s recent failings will prompt this.)
1. The existence of these cards has been widely known about for well over a decade.
2. The DoJ is full of cops as well.
This hypothesis would appear to be disprovable by the DoJ prosecuting cops. (Hint: they do. Including entire police forces.)
Do they exist somewhere else?
The police have wide discretion to issue a warning instead of a fine in most countries as far as I know. But these cards seem to be unique to NYPD. I don't mean that corruption doesn't exist elsewhere but usually it's a little less obvious!
I don't know if it's an actual thing.
Edit: I remember now, it was Jack Reacher season 2.