I've read through the documentation and haven't seen any way to do this, so I'm gonna ask the question and hope that I'm not just completely blind.
I have an event that offers 50% off based on an age range. This discount is off the total price, and it only applies to the individual registrant, so I can't use a coupon. It would be great if fee fields could be percentage based just as the coupons and early bird discounts are.
If I'm just totally missing where I can set this, please let me know.