You can always attempt to call off a KOS after it has been called. However, of the person you call out is damaged due to this KOS, it is an official KOS and may be RDM if there was no reason to call it in the first place. Sometimes a situation comes about when a player calls a KOS, calls it off, then someone says, "You can't call off a KOS" or shows some other acknowledgement to the call off and still kills/damages the called out player. Note: If the damaging player acknowledges the call off and still continues to carry out the KOS, te responsibility falls on the damaging player. If the damaging player is unaware that a KOS was called off, the responsibility falls on the caller. A call off must be specific enough to know what a player is referencing.
Yes, you can call off a KOS you placed. If you do so, someone else may ONLY continue to follow it if they were unaware of its being called off. When someone says "you can't call off a KOS," then they're acknowledging that they heard the KOS was called off and they followed it anyways. In this case, they would be slain for RDM. Generally I use chat KOSes for the purposes of being proven (and because it's easier logistically to prove someone was KOSed,) and call them off by hitting the "No" bind a few times, because that way nobody can say they didn't see it. Edit: Ninja'd by Mango.
I've yet to meet anyone who didn't understand what the "No" afterwards meant. It provides a fairly clear narrative. > See Noctorious shooting someone unexpectedly. "Noctorious is a traitor!" > Noctorious identifies traitor body. "No." "No." "Noctorious is innocent."
To be completely honest, no, it would not. This is simply because players would have no idea what the context of it would be. some players say no when they fall to their death. Some players say no when they've been called out. Some players say no when they're being kill. A simple "Disregard that last KOS" bind would suffice. Calling someone an innocent would also suffice.