Not strictly a company secret, but I had to sign an NDA for it, because... reasons.
I used to work for a massive conglomerate, these guys are making from components for satellites and tank to rubber gloves for hospitals, and everything in between. My job was to help the company implement regulations, work with auditors and generally follow product specific rules.
So I was on these 2 New Product Development teams and because the products needed some very specific testing equipment, we started working with local authorities and some contractors to build the testing station in the future factory. We drafted plans, prepare documents, we had an auditor come and see the place, the contractor came and checked what he needed to do, everything was going according to plan.
While all of this was happening, I was on a separate project where we were working on closing down the above mentioned factory.
I knew my grammar teacher was sus when she was telling us all those rules.