February 5, 2020


WD-40 stands for “Water Displacement, 40th formula,” since the the creators’ 40th experimental recipe fulfilled its intended purpose of preventing corrosion on the Atlas rocket.

The globally-ubiquitous AK-47 rifle is named for it’s Russian designer Mikhail Kalashnikov (AK = “Avtomat Kalashnikova” or “Automatic device by Kalashnikov”) and 1947, the year of its first manufacture.

In the US, a non-profit company is called a “501(c)(3)”, and a tax-advantaged type of retirement account is called a “401(k)” because those are the sections where they’re described in the US Tax Code.