This is "Reader's Digest"...
Perhaps to mean that they will give a discount to the person the piece was sent to... when the next order is received. This might just be the only "denomination" for the British pieces - I think I have one.
I have a French equivalent - Aluminium, multi-sided, VALEUR 849F PIECE MERCI - along with the same logo.
I also have a few other reader's digest pieces (likely British).
Thanks Mr Paul Baker