Found a thread on it on here a while back,
Apparently, they have just added together the two different types of fibre present in the food and called this total figure beneficial fibre.
Though the crude fibre, which is the one that is listed on the packs of most rabbit food, is the same, 19% or similar. One type of the fibre is digestable, the other is not.
This is my understanding of it anyway!
Laura.