Typing a forward slash followed by a combination of letters  will allow you to send messages to the correct target(s)

/l <message> = message to people near you (local)
/r <message> = respond to the last ship that you received a message from.
/t <message> = send a message directly to targeted ship.
/w <message> = send a message to all members of your wing.
/v <message> = send a message to players you are in voice a message with.
/l <message> send a message to all ships within range.
/s <message> = Message to all squadron.
/sl <message> = message to all other squadron leaders (if you have the correct rank).

Colour codes:

Orange: local broadcast.
Green: squadron message.
Cyan: wing broadcast.
Yellow: direct message.
Red: authority broadcast.