You may remember that Royal Mail recently decided that all stamps should have barcodes, and those without barcodes would not be valid after a date earlier this year. They even set up a freepost address you could send your old stamps to, and have them replaced with new ones. If these barcodes are so essential, why is it that when you buy the adhesive postage labels from the self-service machines in the Post Office, there's no barcode on them?