WTF
From RPGWW Wiki
In July 2003, FlamingDeth posted a thread with the title "I am a chef" saying "Hello". Various other posters replied with various greetings, culminating in ladydragonclaws saying "WTF" in a large font. (The thread is so old that it has been pushed off of ezBoard.)
Zemyla took the joke and ran with it, immediately using "WTF" as a greeting in the chats. It caught on quickly, and now WTF is considered one of Zemyla's calling cards.