no they dont. At least not in the US.

Cops can lie with impunity while in uniform, why would an undercover cop not lie to you?

That's a myth purposely spread by cops in order to fool people. Even if it was true, unscrupulous cops looking for promotions would be breaking it like all the other rules they routinely ignore.

That's what they want you to believe.

The Onion shared a much better method the other day. Just make the suspected cop "peacefully deescalate a conflict".

https://theonion.com/gang-initiate-forced-to-peacefully-dees...

Oh Lord, I apologize for being a person almost congenitally incapable of using /s. I had thought/ hoped the idea of an AI "cop" having to tell you it was a cop was ridiculous enough on its face, but it also occurs to me I am of a certain age where that was a very popular legend in the US and that doesn't apply to everyone. I accept the downvotes as appropriate!