Looking over an upcoming race lineup, I see the following (among others):
Cat 4, 44 miles - 8:00am
Cat 5A, 25 miles - 8:10am
Cat 4 / 5B, 25 miles - 11:00am
Does this mean that there are just two different choices for Cat 4 & 5 racers or is there actually a distinction between Cat 5A & B?