Type 2 and 7 have a cap. Type 1 has no cap, but realize that Type 1 is only 5% of all scholarships. If 1000 in total are given out 50 will be Type 1. Traditionally 5K applicants are boarded, so basically it is 1% of all applicants.
To make that number of getting a Type 1 even scarier, if you want non-tech, only 5% of that 50 or 2-3.
Type 2s are 15% of all scholarships, and they are the 18K cap. They allow you to pay the difference if it is over 18K
Also the wording on their cap is very specific UP TO 18K, so if the tuition is 14K, they are only going to pay the bursar 14K, you don't get to place that 4K difference towards R &B.
Type 7 will pay the equivalent to the IS rate, so if you chose a college and your IS rate is 18K, than that is what they will give, if you go OOS or private they are still only going to pay IS. They will not allow you to pay the difference. The only option is to convert a Type 7 4 yr to a Type 2 3yr.
The beauty of the AFROTC scholarship is a cadet can take it to any school, it is not tied to the det. like A/NROTC. The blemish is they really do have a cap for the majority of cadets.