As I recall, the rules allow you to use an ANY PERMITTED ticket on any permitted route where a higher route-specific fare doesn't exist.
What if the route-specific fare is higher for some ticket types but not others? For example, Potters Bar to Stratford London, an off-peak day return is more expensive route HACKNEY WICK, while all other tickets are more expensive on route +ANY PERMITTED.
What if the route-specific fare is higher for some ticket types but not others? For example, Potters Bar to Stratford London, an off-peak day return is more expensive route HACKNEY WICK, while all other tickets are more expensive on route +ANY PERMITTED.