Types of chatting in RF Online are as follows.

Normal Chat Activate the chatting window (then press Enter) and then type in what you want to say.
Whisper /whisper recipient text
(Ex: /whisfer ID hello)
Party Chat /party text
(Ex: /party hello party members)
Guild Chat
/guild text
(Ex: /guild hello guild members)
Map Chat

/map text (to all within the current map)
(Ex: /map hello all)

Race Chat
/race text (only for available to archon)
(Ex: /race hello all)
All Chat
/all text
Every connected player in the same race reads this chat.
(1,000 unit currency is spent per message)
(Ex: /all can everyone see this?)