Darkside, shmarkside.

Have I mentioned that in my opinion the term is silly, and particularly so if you try to apply it from a non-US point of view? But if you try to differentiate between, hmm, "home" coinage and "other" coinage, the first question would be, when did the country in question (say, "X-land") become independent? For the time before, it would be interesting to check whether the country that X-land belonged to had a mint in X-land. If yes, the coins circulating in X-land could be considered X-landish even though that is not really common.
For example, the Czech Republic became "independent" in 1993 since that is when Czechoslovakia ceased to exist. But I suppose that many collectors in CZ consider the CS(S)R coins to be domestic pieces, probably even the Böhmen & Mähren ones, while the Austrian coins ... well, even those made in what today is Czechia and Slovakia are not particularly CZ/SK coins. Another collector may emphasize that everything minted in Kremnitz/Kremnica and used as money in that area is domestic.
Coins from Danzig (Gdansk) issued between WW1 and WW2 usually show up in both German and Polish catalogs. Coins from Saarland can often be found in both French and German catalogs.
In Dutch coin catalogs the pieces issued during the German occupation are usually considered Dutch since they were made in NL for use in the country. In Estonia, Latvia and Lithuania I could imagine that USSR coinage is considered "foreign" as the pieces circulated there c.1940-90 but were made elsewhere and did not say "Estonia" etc. on them. That was different with Russian coins made for Finland until 1917/18, so those are Finnish IMO.
So the answer is: Depends.
Christian