Details on the
FGW▸ leaflet
hereTHe
NRE▸ Site is incorrect - I'll let FGW know.
But the National Rail site
does tell you that the information may not be suitable for your use ...
ATOC» and / or its respective suppliers makes no representations about the suitability of the information, products, and services contained on this Web Site for any purpose. To the maximum extent permitted by law, ATOC Limited and / or its respective suppliers hereby disclaim all warranties, terms and conditions with regard to this information ...
... as I read that, just because it shows a map that shows where a rover ticket can be used, it doesn't mean that it can.