Quick listing of Yahoo IM command codes.

/help calls up the help file
/cls clears the screen
/save saves the current chat session transcript
/leave exits current room
/join roomname joins roomname
/goto username joins the chat room that username is currently in
/follow username user will follows username whenever the user changes rooms
/think text posts text in this format “oO(text)”
/tell username text — allows you to send a text to username with opening a window
/invite username invites username to the current room
/webcam starts your webcam
/version displays the program version
/version username sends the program version to username
/time shows the time
/roll number rolls the number of dice
/logoff closes the client
/ignore add username will add username to your ignore list
/ignore remove username will remove username from your ignore list
:Text formats the text as an emotion

will format the text as the fontface and fontsize specified. Fontsize is in pixels.
<#RRGGBB>Text
colors the text in HEX format