In message , k
writes
Perhaps Ealing Broadway should have
signs on the gates saying that Oyster pre-pay isn't valid on National
Rail, only the Underground.

You mean it doesn't?

Not as far as I've seen so far. It's very lacking in information
altogether (like I've yet to find a timetable of all NR services to
London, outside the barriers). I'll have another look tomorrow.

My NR station (and several others I've been to)
have posters up saying just that.

--
Roland Perry