There are certain airline guidelines and policies that most people know about, such as checked baggage fees, seat back pocket contents, etc., but there are also some lesser-known Spirit rules that you may not have been aware of before now. So if you’re considering booking your next flight with Spirit, here are seven things you probably didn’t know about the airline prior to reading this list. 1) Boarding Process Here’s a fun fact about Spirit: When you board, you must print your boarding pass online or at an airport kiosk, and then go through security. The downside is that if you have a tight connection, it can be tough to make it. And boarding passes are good for only 24 hours after they’re issued. So if you fly in early and don’t print your boarding pass right away, you might miss your flight even though it has a good arrival time listed on Expedia. Some experts recommend getting to the airport at least two hours before a domestic flight; three hours would be better in many cas...