Re: United Kingdom Barcoded postage stamps
I have found the following.
http://aisukltd.com/barcode-verificatio … -barcodes/
I have not read or understood it all yet, but I include the link as it may be that the barcode on the stamps is a particular application of a barcode type that is defined in an international standard.
Wlliam
The Mailmark definition document that I linked to earlier refers to “Data Matrix type ECC200 as defined in ISO/IEC 16022”.
― Tennessee Williams