Chat (manual)
Chat is still limited, but it's got an ever-growing functionality. Here's the basic stuff you can do:
Change channels. Type /c and then the channel you want. Chat recognizes both the name and the number for chat channels. Available channels are: /newbie or /1 -- This is newbie, fun, and games. It's for asking non-spoiler questions and for goofing around.
/normal or /2 -- This is gameplay and trade. For game-related conversations, spoilers, and financial transactions.
Emote. Type /em or /me and the rest of the message. It shows up in italics and always prints your name at the beginning.
Private messages. Type /pm [character number or character_name_with_underscores] [message]. The spaces between the command, the number, and the message are necessary. This will send a private message, which nobody else can see, to the character with that number or that name (names with spaces need to be typed with underscores instead of spaces; example: to send a PM to the character Big Shot you'd need to type /pm big_shot [message]). You will get a green confirmation message, and they will get the message in blue. The /w and /msg commands work as duplicate options for /pm. If a PM is sent to a player who is not in chat or online, or to a number that doesn't represent a real player, the message will be lost.
Send a private message to the last person you sent a PM to. Type /r and the message. Chat remembers who you last sent a messge to. This is not saved between sessions.
Look up a character. Type /whois and the character name.
See everyone in your channel. Type /who and a list of those currently in chat will appear.
Get help. Type /help. However, it's far more limited than this page here, so it's not your best bet.
Leave chat. Type /exit. Or just click the link at the bottom of chat.
Coming soon: the ability to listen to other channels.
Coming slightly less soon: ignore/baleet, and /friend commands.