The section of the NRE relating to Rovers and Rangers is hopeless; often with incorrect or different pricing, ticket descriptions (for example, referring to Cheap Day Returns 10 years after they were rebranded) and, as here, route maps, relative to other official sources, such as TOC own websites and local PTE websites.
Indeed, there are so many errors, including the anomaly of the apparent differential validity between 'West Midland Day Rangers' and 'West Midland Family Day Rangers' that a passenger could reasonably conclude that an omission of a TOC from the supposed 'list of participating operators' is just yet another error or omission, rather than a definitive statement of (in)validity.
The NRCoT states:
http://www.nationalrail.co.uk/Conditions of Travel 2016.pdf
13.3 Your Ticket may show that it is valid only on certain train services, such as those of a particular Train Company, or on trains travelling via a certain route or routes. If no specific route or Train Company is shown, then (subject to any time restrictions for the type of fare you have purchased) it will be valid on:
a) any direct train service between the station(s) shown on your Ticket;
b) by any services (including any change of trains) over the shortest route which can be used by scheduled passenger services between the stations shown on your Ticket;
c) any other routes as shown in the ‘National Routeing Guide’.
Since no such restriction is shown on the ticket, which is routed "Any Permitted", my view is that the ticket is contractually valid on all franchised operators, subject only to published time restrictions, and that a franchised TOC cannot "refuse to accept" such tickets any more than they can "refuse to accept" CDRs or SVRs.
Even if I am incorrect in this belief, it is clear from the differing information from different official sources that there is considerable ambiguity as to the terms of the contract entered into, and the Consumer Rights Act 2015 and the principle of
contra proferentem both mean that the customer is entitled to the benefit of the most favourable interpretation of the terms of the contract for travel.