Thanks for the responses-
I have done a little research and found out that letters from the end of the alphabet, when coupled with an approach type, denote that the approach can NOT be used at all times, or some type of restriction. The approaches with letters from the beginning of the alphabet denote an approach that is not a "straight-in". If you look at the VPS charts, you will see in the notes, that the ILS' are not authorized at all times. I'm assuming this is because of the high military activity in and around the airport. The final approach course also goes right through a restricted area.
Just some little tidbits for you! By the way- I thought this chart thing was a one-time purchase, what do you mean updated?!
