Lore question: "Never attack a Yath"

Okay, just wondering here what the extent of that is in the culture. Since we obviously don't have the setup for the classic Salvatore-style house wars where everyone's killed cleanly with no trace, we do see fights break out. And if a fight is between yath... is it culturally acceptable to step in and help the senior Yathrin, or whichever one you're personally alligned with, take out the other? Is there a point where it's all right? I'm just trying to make sure I know, since it's obviously something a good lolthite character would know, even if the player doesn't.

Most time Yath keep fight to self and not let other see what happen. In public place do not attack Yath if you not also Yath. In private place kill kill kill for malla Lolth