Apart from simply being curious I am trying to protect myself from mistakes, either mine or those of railway staff members.
I have no intention to game the system - I have a season ticket that I use for my daily commute (I’ve asked some question about it here), so doing anything dodgy would make no sense to me. I don’t spend too much on public transport anyway, so even if somehow avoided paying for it altogether I wouldn’t gain much to justify the risk.
I have never had any issues with revenue inspectors - during my four years in London which includes a daily commute I’ve encountered them two or three times where they simply checked my card and moved on.
But we are all humans and we can make mistakes. I can mistakenly travel outside the validity zone of my season ticket by simply boarding a train, which is going to the same destination as mine from the same platform, but doesn’t stop at my station. I can touch in with a wrong card and then travel on a route where the card that I used to touch in is not valid, but the other card would be valid if I touched in with it. I normally travel in a declassified first class compartment with my second class ticket, which is OK, but if one day the declassification is cancelled or due to a disruption a train with a “legal” first class stops at my station I can travel there without realising I am legally in the wrong. Or even if I travel in a declassified first class, the display may still show “this area is only for first class ticket holders” and I think that there’s a change that an inspector may try to wrongfully issue a penalty fare.
And I have no desire whatsoever to get a conviction. I am in the UK on a visa and having troubles with the law enforcements is the last thing I need.
So I was under impression that I was protected from being disproportionally penalised for such mistakes. Apparently, I am not, and there’s nothing stopping a train company from launching a prosecution. Now I am trying to figure out what would be the best course of action if I ever get in troubles with an inspector if any of the situations above arises, especially if I think that they are in the wrong, not me. Should I just shut up and pay whatever they tell me? Should I dispute a penalty I don’t agree with or should I be more careful not to aggravate the situation? This is what motivated me to start this thread and ask follow up questions.
I don’t like walking in a minefield without knowing the chances of stepping on a mine and the damage it may cause.