This led me to wonder whether there was listing of Oyster Card codes and whether it was worth knowing what they meant.
Naturally, someone (@markylon) has come up with a listing of Oyster Card codes that looks pretty comprehensive. There's almost a hundred codes covering a variety of things that can happen when you pass through the gates at a Tube station.
Some of my favourites are "82 - Illogical use of ticket" - the mind boggles as to what that would be. "33 - Illogical interchange through gates", also got the person who published the listing thinking. But he elaborated. An illogical journey is not taking the Tube from Covent Garden to Leicester Square (why would you want to do that?), but "is when, say you exit through Monument station and re-enter at Tower Hill"!!!!
There are also error message 61 - 63 which are for spending too long at an interchange, on a journey and on a platform. Just how long is too long to spend at a station? How many hours? What if you'd had a long day & fell asleep?
Error message 41 was also puzzling. "Zig Zag through gates". Does this mean something like going through and then immediately coming back through the same gate? Would you even have long enough to do this before the barrier closed behind you?
If you know of any other messages which are not on the list, let us know. Or if you can think of any activities or behaviour such as "Taking too long to go through gates" or "Trying to take a huge amount of luggage through the standard gates", of which there should be error codes for.