Complex sentence: The main difference between ski flying and ski jumping pertains to hill design, as mandated by the FIS: historically, hills with a K-point (German: "Konstruktionspunkt") or main landing zone of more than were classed as ski flying hills.
Split into simpler sentences: The main difference between ski flying and ski jumping pertains to hill design, as mandated by the FIS. Historically, hills with a K-point (German: "Konstruktionspunkt") or main landing zone of more than were classed as ski flying hills.