Tonight, I caught one of the new www.ns.nl trains. I sat in the voorang fiets area even though I had my folding bicycle and could sit anywhere. (It was before full sized bicycles would be allowed on the car.)
After a few minutes, I noticed a seat belt that could go across the three seats.
My reaction was to get up and needlessly strap my bicycle into the area.
Then I got over it and sat back down with the bicycle between my feet.