Dave Newt writes:

You're supposed to carry your record-card with the ticket I believe.

Which if you renew online you don't get. Are we supposed to carry an A4
printout of the website receipt everywhere we go now?

The station staff told me to keep the record card in a safe place
seperate from the oyster card. Its basically a receipt in case the
card gets lost. If an inspector wants to check its validity, they'll
have to have a reader with them I guess (although the ones I saw at
South Ealing the other morning didn't have readers and just waved
people with oysters past).