On using your Oystercard on a bus...

First things first. It's not a bog-standard single lump of plastic cut to card-shape. It's actually several thin layers, bonded together to form a composite 'near-field' RFID card.

That means it's got a small computer chip inside the card, linked to an antenna, also built into the card. It's all 'passive', and doesn't need a power source. When it's held to ("touched") a card reader, the card reader does all the work, and using radio technology, gets the required information off the card, such as the amount of money to pay the fare, or if it's got a period pass on the card, that it's in date, and so on.

For the teenagers amongst you, that means that if you're on this apparent 'plastic diet' where you seem to chew or nibble the edges of the card, don't be too surprised if the damn thing stops working, as likely as not, you just chewed through the antenna in the card, and may well have to stump up £2.20 in cash to buy a ticket. We can't take your word that it's valid, as it *may* have been stopped for certain reasons (can you say "anti-social behaviour" and "free travel withdrawn"?).

Anyhow, here are the audio clues to listen for, when you touch (not slam, bend, or pound) your Oystercard to the reader unit...

• One 'Bleep' heard from the reader:
  All OK, carry on and try to find a seat on the bus.

• Two 'bleeps' heard from the reader:
  OOPS! Something's gone wrong, either the card couldn't be read, or it's not got enough money to pay the fare, or something. See the driver, anyhow.

• Six short 'bleeps' heard from the reader:
  Child rate pass. If you're an adult and the driver hears this, you've got a problem!

An additional clue is the little light above and to the left of the reader unit. Normally orange, if it turns red and you hear those two bleeps, then you have a problem. See the driver. If it turns green (one or six bleeps), carry on, all is well.

Oh yeah, if you get the two bleeps, don't argue the toss with the driver. He or she has to take the machines' word for things. We have very little discression in this - and those of you who ask for yellow tickets ("Unpaid Fare Notices"), you're chancing your arms - we're only supposed to issue those in exceptional circumstances, such as for the elderly, those in distress, young kids, and similar: They're not supposed to be used if you "forgot" your card, wallet, or whatnot. It that's the case, then tough cheese, get off and walk. It's your fault you forgot the where-with-all to pay for the trip, after all. Man up (as I believe the term is these days), and take the fault on the chin, like the rest of us.

I hope this helps clear up the confusion some of you seem to have!