Good question. I don't really know. Perhaps it's subjective. For me, I'm going with what's on the category description on this forum. While I can't use my hair as a rope, hip+ length hair isn't too common in real life, just like how almost no other heroine in fairy tales has the same length hair as Rapunzel. Erm, so I guess "Rapunzel length" could be any length that not too many people have. Maybe.

Sorry if that didn't make sense. I'm having problems putting my thoughts into coherent sentences this evening.