All I'm suggesting is to consider the whole sticker. I read "it" as the engine. Especially with the larger font and all caps.
THIS ENGINE HAS PASSED a
SPECIAL ELECTRONIC QUALITY CHECK
So I'm open to the possibility that some sort of electronic machine was used for whatever they tested. It could have been compression that had a go/no go signal or maybe even recorded the pressures. Or, maybe they test ran the engine and had an osilliscope on it. Lots of possibilites that's for sure.
