o yeah . . .
There are a lot of funny rules out there.
If you play Out of the Box rules, you still should acquaint yourself with the OFFICIAL FAQs.
If you play in tournaments, you will probably already be familiar with Larry Harris Tournament Rules. Which I feel are perfectly well and good, but still unofficial as far as Hasbro/WotC/Avalon Hill is concerned.
Cousin Joe has “Enhanced” Axis and Allies, which fixes unit costs for balance.
Some tournaments place special values on territories. Yoper would know more about that; check out the smoreyswamp site.
If you play online, you should familiarize yourself with Larry Harris Tournament Rules, the bidding system (open and blind), and the various programs (MapView, I think some others).
Personally, I play OOB/FAQ with no NAs (because NAs are considered optional) on TripleA.
I haven’t found any face to face opponents in the area, but I figure there are plenty of people in New York City, I’ll probably find somebody eventually.