There must be some rules that determine which set of localized strings of an Apple Wallet pass (.pkpass) is used when the choice is not obvious.
For instance, I made a pass with localization folders
ko.lproj (Korean)
pl.lproj (Polish)
zh-Hans.lproj (Chinese).
If any of these languages is in my iPhone's preferred languages (Settings... General... Language & Region), then it's easy: the first one on that list is used. But what if the list does not have any of them?
When I try, it seems the Chinese localization is chosen by the Wallet app. Without the Chinese localization folder, it is Korean. If I also add
ar.lproj (Arabic)
then Arabic is chosen.
I can't discern any system here. How does Wallet choose the default localization?