Standard Gauge wrote:

I was reading something on the net about the layout of Stratford station
on the Central Line. I have been there before a few years ago, but I
don't remember the layout myself. The page indicated that it's possible
to transfer between Central Line trains and mainline trains across the
platform. Doesn't this imply that it's possible to board a tube train
without entering a fare-control area? If so, how does one get charged
the proper amount on one's farecard upon exit on the other end of one's
journey?

If arriving at Stratford on a mainline train and using an Oystercard to
continue your journey you need to touch in before boarding the tube (or
v.v.) - there are around 6-8(?) readers on each of the Central line
platforms.

It's not the easiest thing to remember - IME, it's easy to forget to
touch in/out on the DLR if you only use it occasionally. Much better
when gates force you to touch in/out at system boundaries.

Perhaps these standalone Oyster readers could have an
illuminated/flashing sign to remind us forgetful types?