Self-seeded A & B races alternate in multiple short track-inspired races.
Great practice and a great workout for beginners and experienced racers alike.
A Race, B Race, or???
Unless turnout is huge, women and men will race together. A Race/B Race.
Generally, the A Race is for stronger, more experienced racers, maybe Cats 1-3. The B Race is for newer racers, say Cat 4 & 5.
Juniors are register separately because they race for free; they will likely race the A & B Races rather than have their own category. That said, based on turn out a C Race, or seperate Juniors or Womens group is certainly possible.