The Chapter Leader has the ability to set a registration deadline for each event. You must register before that deadline or else you probably won't be able to play.
The reason for this, is that golf courses somehow think they're doing us a favor by "allowing" us to clog up their course with paying customers.
Not only will they jack up the prices on us, they sometimes make CL's pre-pay, so please do you part and register as early as you possibly can! It makes life easier on your honorable Chapter Leader.