10. ... from Smitham to Redhill
This one is odd, as Smitham station was renamed Coulsdon Town ten years ago. So the journey would now involve routeing via a time warp.
But there is an anomaly (you could call it a typo) in doubleback easement 700321:
Customers travelling from Tattenham Corner, Tadworth, Kingswood, Chipstead, Woodmansterne, Coulsdon South and Reedham to Redhill and beyond may double back via East Croydon. This easement applies in both directions.
This applies to all the stations on the Tattenham Corner branch, allowing a change at East Croydon rather than Purley. Except it misses out Coulsdon Town (the new Smitham) and substitutes Coulsdon South. Whether and when that longer double back would be really needed I'm not sure, but today with so many cancellations there are some big gaps without it.
What have the journey planners been fed with? Well, the
OJP▸ won't even sell a single ticket (SDS, any permitted route) from Reedham to Redhill, which is listed in the easement, for an itinerary via East Croydon. It insists you need two tickets at £4.60 each rather than one. So what it says about CDN-RDH isn't going to tell us anything.