Infelicity with the browser UI: the symbols by the usernames are unexplained

[LinuxOnTheDesktop]

It would be good were the browser UI to explain - at least via its help button - what the symbols by the usernames mean.

For one thing: what do the coloured circles mean? I had a green circle next to one user and another green circle next to another user, though just now one of those circles changed colour to yellow. Say what? Perhaps it is to do with two of the users being on the same IP. EDIT: OK, grey circle with a minus sign in it means someone has left, but I still do not know what a yellow circle means.

Also, what is the import of the little hyphens - or are they chevrons - next to the circles? They look somewhat clickable but they turn out not to be.

[I had something about the 'connected to server' banner here. I've given it its own issue: #200 ]