Update: after discussion with @PS, I decided that if an edge case arises, I will check Wikipedia and Western media and see if they consistently describe the conflict in question as a civil war. Also, if in doubt, I may or may not temporarily freeze the market and consult the traders, and/or resolve N/A.

Would the Chechen wars count?
How about the Serbia-Slovenia war?

@a2bb Man, I don't know. I'd definitely invite the traders to discuss any edge cases, perhaps resolve N/A if the resolution wasn't obvious. I don't think the Chechen wars are usually described as civil wars, for some reason. As for the latter, are you referring to the ten-day war?

@wadimiusz Yes, that one.

@a2bb Interesting edgecase. Also dunno. I think the ten-day war itself is also not usually described as a civil war? So I lean towards no in this case as well.

Some part of Russia declaring independence and an independence war breaking out is definitely a possibility. I think I'd have to freeze the market and discuss with traders.

@wadimiusz I know I'm a bit late to this thread, but I think it's better to do the discussion beforehand, since the edge cases make a big difference to the probability. Apart from the question of whether an independence war would count, there's also the question of whether and when something like an insurgency would be a civil war (I assume Wagner wouldn't have counted).

You could either try to define at least approximate criteria, or try to go with something like "if Wikipedia/Western media consistently describe it as a civil war"

@PS the "wikipedia / western media" thing seems like a good idea...