Interestingly, per General Rule 16.2 the IHCA class rules, tapered sheets are illegal except as allowed within the specific rules for the following boats:

Hobie Dragoon
Hobie FX-One
Hobie Tiger
Hobie 20
Hobie Fox
Hobie 16 (for the kite only)

They are also specifically outlawed by Hobie Wave Rule 5.1.

Does that really make any sense?

Mike