Just remember that the rules say this and the rules say that, but I can guarantee you some rules are stretched a bit based on the category of airport and FSD. For example I know for a fact that at my terminal at JFK; and the many other terminals I worked at, it's the airlines who handles the number of carryon bags. That 1+1 you can get that strictly from an airlines website also. Maybe some airports TSA enforces it, but I know at JFK it tends not to happen. Now if a bag is too big to fit through the x-ray machine, then more than likely it's no carryon bag....now we all now if you travel a lot big bags like that wont fit in the overhead compartment. If it gets through TSA, I can tell that if it's going to be too big then it's going to get gate checked.....how do I know I use to do that stuff when I worked for Swissport. So yes the TSA Website says this, but where I work does it get enforced by TSA, not one bit.