Here's an appeals decision:
A boat that hails for room to tack before safety requires her to tack is entitled
to receive room under rule 20.1(b), but by hailing at that time she breaks rule
20.3. An inside overlapped boat is entitled to room between the outside boat
and an obstruction under rule 19.2(b) even though she has tacked into the
inside overlapping position.
The USSA Book is available on their website: Appeals