I worked for the 3-letter operator in the Gulf of Mexico. When I was hired, the company made me an individual salary offer with regular raises, strictly confidential! Discussing compensation was a firing offense!
When one worked overtime, one would look up their salary by position and length of employment, hourly, daily, etc., in a book in the lead pilot's office. Wait, what? Everybody was paid the same yet we couldn't discuss salary or we would be terminated?
Did that mean we couldn't tell anybody our date of hire?