printing plates (GanS 6)

Back in the good ol' 1970s and '80s, this quaint technology was used to print a book. Curiously enough, the same technology could be used to prevent the printing of a book—by destroying the plates.

(Not that this was ever done, of course! Just to hinder other forms of Cornish than KK® or anything? A vile and baseless canard, I tell you!).

See 'obscurantist vocabulary', 'cuckoo'.