When you buy a ticket to travel on the railway network you enter into an agreement with the relevant operating company. That agreement gives you the right to make the journey between the stations/zones shown on the ticket you’ve bought.
The National Rail Conditions of Travel are also part of that agreement.
They set out the minimum level of service you are entitled to expect when you travel.
Within the the National Rail Conditions of Travel are references to a Code of Practice for meetings arranged in connection with duplicate Season Tickets. A copy of this can be found below.