In theory at least, someone checking tickets on a fast line service could ask why you don't have a reservation for that train.
This is something I have done before - choosing an unreservable service for part of the journey to circumvent quota restriction, obtaining a paper ticket such that the train wouldn't be printed, and travelling on a fast train on that portion of the journey.
This may come in one of the following two forms:
1. I choose an unreservable train, for example, Woking to Basingstoke, to connect to a reservable train, for example, Basingstoke to Bournemouth, when choosing another reservable train for that portion will push the price up. I eventually travel on another reservable train on the portion without a reservation, i.e. Woking to Basingstoke, in order to connect to my booked train from Basingstoke to Bournemouth.
2. I choose an unreservable train to connect to a reservable train, for a journey which can be done wholly on the reservable train, for example, Stratford to Norwich by forcing a connection from an unreservable train at Colchester, when making a reservation for the whole journey will push up the price. I eventually travel on my booked train from Stratford to Norwich without making a change.
I have got my ticket checked by the guard in scenario 1 above and there wasn't any problem at all, with the guard just telling me to change at Basingstoke.
Can anyone tell me if the above is officially allowed or not, i.e. travelling on a reservable train for the connection bit, when no reservation is made?
I can now think of the following examples:
1. Someone buys an LNER & Connections ticket to travel from Clapham Junction to York. The Clapham Junction to Victoria connection generated by the journey planner is on a reservable train, which is then printed on the ticket. According to the rules he must travel on the exact train from Clapham Junction to Victoria, however, it is not possible to identify the train as they don't run to a schedule, and eventually he gets on a wrong train. He is then penalty fared by a Southern revenue inspector.
2. Someone buys an LNER & Connections ticket to travel from Clapham Junction to York. The Clapham Junction to Victoria connection generated by the journey planner is on a unreservable train, which is not shown on the ticket. However, it is not possible to know if a train is reservable or not at Clapham Junction. He boarded the first train towards London Victoria and it's, unknowingly to him, a reservable train. The inspector then questions him if he is travelling according to the itinerary because he should have a reservation on that train.