In message e.net,
Mark Goodge writes
On Tue, 19 Sep 2006 18:13:47 +0100, Brian Morrison put finger to
keyboard and typed:

Mark Goodge wrote:

Except that they're not unique if they can be printed multiple times.

The barcode is unique to the purchase. Once scanned on its way through
the postal system, it will generate an error if scanned in again and
hence prevent re-use of the same code.

Yes, but with the inconvenience on the addressee rather than the sender.

They can refuse to accept it.

Unfortunately 'they' don't know who it's from or what it is until
they've gone to the sorting office, at which point they've already spent
£2.00 on petrol and half an hour of their time, so might as well pay the
1p shortfall + £1.00 fine to get it while they're there anyway.


--
bof at bof dot me dot uk