Theoretically, what would happen if the customer pointed to the following wording on the rear of their ticket, though?
"+" denotes ticket is valid for one journey across London by Underground/DLR services if required.
Can a customer then claim that the route on the ticket cannot prohibit use of the Tube when the ticket has a Maltese cross, on the basis that it clearly states that this means it is valid for a journey on the Underground
if required*, and that the ticket is neither restricted by use of a TOC as specified in Appendix C of the NRCoC, nor via a particular NR rail route or location?
Common sense would dictate that the customer should not use Tube services, but then again, their ticket does clearly state that you may use tickets with a Maltese cross on the Underground/DLR. Surely the most beneficial route should be permitted (presumably often the shortest or quickest) if the record of the contract (the ticket) is contradictory?
*This specific requirement is, I believe, not clearly defined.