A Jaffa revenge oath. The term literally translates as "revenge by the wearer of horns."
Family - Bra'tac warns Teal'c not to declare kelmar'tokim against Fro'tac, a Jaffa who has married his wife, Drey'auc.
Fair Game - Teal'c declares kelmar'tokim against the System Lord Cronus, who once murdered Teal'c's father.
Orpheus - The warden of a Jaffa prison camp verbally insults the men in his charge, mentioning "kelmar'tokim."