Originally Posted by stut

There are some anomalies, but you need to be careful if the train doesn't stop at the named station. While most train companies in the SE have pretty much always let it pass, some have now stated that they will not accept this (this was after several people discovered they could significantly reduce the cost of their season ticket by doing so - e.g. at Hadley Wood).

(FWIW, If you're using a point-to-point season ticket as part of your journey, you can split your tickets as much as you like, and you needn't be on a train that calls at that station. However, Travelcards are a special case.)