This arrived this morning. It looks like a normal 2nd Class Machin stuck on an envelope but it isn't. The stamp design has been printed on the envelope and it also looks as though the cancellation and other entries below were printed at the same time.
I remember Machin design 'stamps' being printed on envelopes and cards years ago but I have not seen anything like this at all for a long time and certainly not featuring something so similar to a current 'normal' stamp. Even the perforation has been printed and that I certainly don't recall noticing before.
The use of a QR code suggests it isn't an ancient type of label being used rather later than intended but something reasonably of the moment.
It would be nice to know what this is all about. Is it someting commercial organisations can buy in bulk? My guess is that it has been printed by the organisation under some kind of licence (like we can print our own labels on-line). I tried tweeting and mentioning @RoyalMail which usually gets a response but nothing of help has appeared so far and it will now have disappeared from everyone's streams anyway.
It may well be that some of you get hundreds of these and have been getting them for years and my rather limited amount of post has precluded my seeing any. A brief note as to what others we should look out for would be appreciated from those who know.