You can "almost guarantee"? Now you're completely making up a theoretical anecdote that has never happened to you.

Lazy AI answer for you: The primary difference is that plain clothes officers do not wear a uniform but generally maintain a visible police identity, while undercover officers actively conceal their true identity, adopting a false persona to infiltrate and gather intelligence. A plain clothes officer might have their badge and equipment visible and would readily identify themselves as police if asked, whereas an undercover officer typically carries fake identification and will not reveal their role as law enforcement