The white x in a red circle next to player names

As a tournament director, one can go to a list of the participant names and see various information including the win-loss-draw record. There is an x in a circle next to active players and I wonder what pressing that will do. I do not want to experiment and press it as I do not want to (possibly) inactivate or eliminate active players who are playing a game (which I assume might be the purpose for the button).

So what does that button do?

I haven't run a Daily/correspondence tourney here yet but I believe that removes them from the tourney. 

What is the little green square you see next to a member?

It means they are either online or recently were (and didn't log off ). If the support pages start acting better, I'll post a link too 

Martin, there's also a yellow square that shows up. I always figured the green square meant a person was online, but never found out what the yellow color means?

What is the purpose of being allowed to remove a player from a tournament?

I think it is supposed to be orange and that means they are in Live.

https://support.chess.com/customer/en/portal/articles/1444855-what-is-the-difference-between-the-green-and-orange-square-on-my-profile-picture-

To your second question, I think most of the time it would be used to remove someone that may have been rated correctly for the tourney when they joined but not by the time it starts. There could be other reasons too.

White X in red circle means a players account has been closed. Normally this happens when an individual is using a chess engine or cheating device to get an advantage. Why cheat when you can lose with good grace. At least I know I made the moves, either good or bad.

Yes Marc, cheaters should be punished. But I was referring to that symbol next to the names of all players in a tournament if you are the tournament director. You will only see this if you are directing a tournament and have an option to see the list of all the player names.

Right,that's to remove a player. There rating may be wrong,a player might ask you to remove them,you may not like them,whatever. If the TD removes someone before the tournament starts,they will not be able to rejoin.

Then what does it mean if a x mark in white circle next to players username