Topic name explains it all.
When a person dies (Anonymous Victim) this is what the chat message would look like:
Tyler66 [Death Icon] Anonymous Victim
When a person kills (Anonymous Killer) this is what the chat message would look like:
Anonymous Killer [Death Icon] Tyler66
They could be disabled/enabled anytime from RTB Server settings. If both are enabled; both the Killer and Victim names will not be shown on kill/death.
And obviously, if both are not enabled; the killer and victim will not be anonymous.