- Did you mean the NPC named "Whisper"?
A whisper, or tell, is a private message sent from one player to another, often denoted by the color pink in the chat window.
PST
WoW Manual Scan
PST is an acronym for Please Send Tell. It originates from older MMO's such as EverQuest and even older text based MUD's. It is often mistaken for the sound 'pssst' in WoW. This is why some people will find saying things such as 'please pst me' to be wrong.
- /whisper <player_name> <message>
- /w <player_name> <message>
- /tell <player_name> <message>
- /t <player_name> <message>
All four commands are functionally the same.