DeathMsgTextPlayerKill=Death: %victim was put out of action by %killer (%type)
DeathMsgTextSelfKill=Death: %victim has suffered a self administered loadout error (%type)
DeathMsgTextNPC=Death: %victim did their best.
DeathMsgTextSuicide=Death: %victim has suffered a self inflicted catastrophic decompression.
DeathMsgTextAdminKill=Death: %victim failed to pay his lemon tax.
There you go. Suicide means you crashed into something, self kill means you killed yourself with a weapon.
Remember to pay your lemon tax, kids.
Edit: Hey look, I posted almost the exact same thing in this thread like 6 months ago.