John Woo fought to keep the slash in the title, so moviegoers wouldn't think it was a film about hockey.

One of John Woo's directing styles is to mark large action sequences with doves. You can see this in Mission Impossible 2 on the island just before the final action sequence and in the church after the funeral in Face/Off.

The prison that Castor & Pollux are in is called Erehwon which is "No where" backwards.

One contributor was stationed at George AFB near Victorville, CA where the airport scenes were filmed. The base closed in '92.  Here's something if you really want to get technical - they fight inside a hangar and then to the hush house (engine testing area where Cage is blown into the wall by the engine afterburner).  It looked as though they went through the hangar straight to the hush house. He worked in both of these buildings and had to either drive to the hush house or walk very far across the flight line. Looks good in the movie, unless you were there...