Post here when you are traveling internationally and would like to trade regionals. Remember that you actually have to be within 100 meters of each other to conduct the trade. Also remember that unless you are already at least an Ultra friend with that person it will cost an insane amount of dust. So once you know you will be traveling, strike a friendship here because you will have to gift each other everyday for some time to reach that level.
I’d also like to reply to my own topic that with all the restrictions Niantic put on these trades, you’d probably be better off just catching your own regionals when you travel. For example, where I live, I encounter multiple Tauros each day. I actually like how Niantic has made it almost impossible to create a Black Market with this.