Hello, i cant seem to find a thread to ask this question. my apologies if there is one.

I recently wanted to put in an app for my dad for Global Entry, i came across some stuff i wasnt sure of. There is one country im not sure if it needs to be reported or not.
He went on a trip to Croatia, since Croatia is split up towards to south end of the country, they basically had to get stamped to enter Bosnia, and then back into Croatia again. Im curious if he should report saying he had entered Bosnia or not. or is it just better to list everything just incase. I noticed they also stamped his passport while in transit(Swiss, Zurich). report those as well?

thanks.