Stormtroopers of Death (S.O.D.) Album art...."NHCY" meaning

[Castle_Romeo]

When I was a kid my older brother would make me listen to this album, "Speak English or Die" and at least on vinyl, the liner has the lyrics printed on it and in gray, a gray "X" with "NHCY" in each corner. Still can't figure out WTF it means. Does anyone here know??

LINK:
https://cloud10.todocoleccion.online/discos-vinilo/tc/2018/11/10/13/139622366_111422010.webp