"Clive D. W. Feather" wrote in message
...
Getting on the tube at Tottenham Court Road just now, I noticed that one
of the little advertisement posters had a small sticker on it, as is
sometimes done by protesters of various kinds.

Except that this one said something like:

Using prepay on your Oyster? Always remember to touch in and out
by putting the card flat against the reader.

Huh? Who would do this unofficially? Yet why do it officially?

Sounds more likely that some wag has taken the sticker off a ticket wallet
and stuck it on the nearest suitable spot