Belgian Railways allow you to use either the shortest or quickest route:
http://www.belgianrail.be/en/customer-service/FAQ/tickets.aspx?cat=travel
so it isn't completely obvious to the laymen that the quickest route isn't valid.
http://www.belgianrail.be/en/customer-service/FAQ/tickets.aspx?cat=travel
so it isn't completely obvious to the laymen that the quickest route isn't valid.