While looking for the source I found this comment amusing. https://www.everyoneinbetween.com/2018/02/how-to-travel-in-e... "But bilateral travel agreements are weird. Mostly because there is little to no official information about them available for travelers! This is most likely because countries want them to be forgotten since they all date back to before the Schengen Treaty came into action for them (in the 90’s most likely)."

Here is your source. Not the best source, but I couldn't find my original on the Polish website https://www.gov.pl/ Well, honestly since I'm not in Poland it's just not worth looking for...

https://en.wikipedia.org/wiki/Visa_policy_of_the_Schengen_Ar...

Legacy visa waiver agreements for Annex II nationals[show]