Plate Incriptions GB Booklet

Do these plate inscriptions show up on every booklet pane?
I have quite a few other different booklets and none of them have these numbers

DJD-David

those look like the bottom pane from a sheet of stamps.My guess is that it happens one out of twenty panes or once from how many panes make a sheet from the printer .Much like the old traffic light blocks .

The plate numbers do not appear on every booklet, but their frequency varies with the design of the printers sheet and the machine used to print them. I can't be certain, but on the booklet you have illustrated I think they appear on every eight books.
With some older issues they appear on every ten or twelve booklets.
Normally having a plate number on the booklet commands a premium when selling it.

No cylinder numbers on my booklet pane. As Anglez mentioned it would depend on how the panes were printed. These £1.62 booklets were printed by Walsall Security Printers and were the ONLY source of the self-adhesive World Cup stamps S.G.# 2293 and #2294. The pane number is S.G.#2293a

Thank you all so much
DJD-David

The W in W1 standing for Walsall