On my Nitrado Ark server control panel I can see a list of people who have visited my server, which provides such information as their console ID and their Internal ID. It's called "Player Control".
However, I have noticed that there are a few players who arrive on my server, play for a while, and yet they do not appear on my players list, even a few days after their logging off. Why is this? It would make the banning of these examples difficult.