I thought the part of the "cylinder" that the "plug" was in was called the "hull". The plug and hull together were the cylinder. If I'm wrong, I'm glad to be corrected, thanks. Please, what is the correct terminolgy ? "Bible" is a word I've yet to see in this context.
That was sarcasm, based on the debatable notion that not sharing information about how locks work enhances the security of them. I am of the opinion that security through obscurity is a falsehood, but there are many regular posters to this news group who don't agree. And some of them have reasons that sound very convincing.