Yeah, the first one is kind of nothing (as long as the mark location is taken figuratively and not literally, it could even mean something like a phone number),

Yeah, the first one is kind of nothing (as long as the mark location is taken figuratively and not literally, it could even mean something like a phone number), but the second one kinda came to the forefront around 2022 when governments started talking about vaccine passports and the possibility of using them to deny access based on vaccination status.