Contracts
The famous Van Halen brown M&M clause teaches us that the devil is in the details, and may come back to haunt you, this Halloween, or next.
As you munch on a brown M&M this Halloween, don't forget the contractual significance of that particular piece of candy. The brown M&M was famously used by 80s rock band Van Halen as a test for whether people read their contract, and paid attention to the details. If the devil is in the details, then, in this story, the brown M&M is the devil.
Buried towards the end of their performance contract, Van Halen added a series of food and refreshment requirements. One item, under the heading "Munchies", stipulated M&Ms, with the added comment "absolutely no brown ones". David Lee Roth has since explained this was not because anyone hated brown candy. Rather, it was a way to know which venues paid attention to the contract details, and which didn't. If they went backstage and found the offending candy, they would know they needed to check everything else, like electrical, structural and other requirements for their fancy equipment. They might also trash the dressing room, just to make a point. I guess the same would apply if there was no herring in sour cream, or only one bottle of Blue Nun wine, instead of two.
The Halloween lesson for the rest of us? Beware the details buried in the dark corners of your contracts. Make sure you know what you've signed up for, and make sure you follow it. It may come back to haunt you.