I don't usually use the chat, except when saying hi or answering a question. I susually talk in battles, and it's pretty much really basic. People with a + in their name are like, VIP, and others with &, % and ~ and really really VIP.
:O well that's strange. I never really experienced something myself. I think you should try on going on the Pokemon showdown official server first, then try making anew account (put a z in the end of your name, for example).
I'm still learning it, no idea how even the chat works.
I was hoping you'd explain... and help me fix the issue where I lose connection with the server and have to wait an hour for it to let me use my username again.