I wished I could find the photo, otherwise you'd not believe it.
Local council, for which we were working, had signs made up.
Nice job too, proper decent quality, Good materials, clear lettering.
Signs with the warning:
"Encapsulated asbestos : do not drill".
Signs had pre-drilled holes in each corner, so that whoever put them up could drill-and-plug and fix them.
They were drilled, plugged, and screwed into the encapsulated asbestos.......