My friend recently applied and was granted a visa for a meeting he's attending at a USA university. His visa has some annotations in it. One of these annotations is an airport code (IAD). He was part of a group and apparently they listed IAD as the nearest airport to where they are traveling to.
I was helping him find tickets and I realized that he'd get much better prizes if he travels via BWI (it's actually 5 minutes closer to his main destination, according to Google Maps). My question is, can he travel via BWI or is it a MUST that he enters the USA via IAD? Also, seeing how most trips first enter the USA in places like Miami/New York, does it matter what his visa says? Or does it mean he needs a direct (and quite expensive) flight to IAD?