USCF/FIDE ratings

I am reposting here a question that came up on another chess website posted by a NM who is not a current member and played tournaments in Portugal.

and later

I can think of some answers but I am puzzled how tournaments abroad find their way into the USCF ratings. I would appreciate if someone is able to answer.

Please see the topic on this issue (USCF Rating Foreign Tournaments) in the All Things Chess Forum.