Sorry for the delay. Category list can be found here. PLEASE NOTE that adjustments have been made up and down based on performance last year.
If you are not on the list you must race in the C event unless you gain an exemption from the cyclocross committee. That can take time. Apply to Gary Sewell ahead of time.
When you pre-register online, the CCN system cannot tell if you are in the correct category. It may let you to register for a category you won't be allowed to race in. If you accidentally sign up for the wrong category show up for your proper race and an adjustment will be made at sign-in.