I'm pretty sure the title was a bit tongue-in-cheek, but at the same time, it's a definable, historical legal term. Better than titling it "An informal agreemen

I'm pretty sure the title was a bit tongue-in-cheek, but at the same time, it's a definable, historical legal term. Better than titling it "An informal agreement between two or more parties simply understood as part of an unspoken agreement by convention or through mutually beneficial etiquette." (Apologies to Wikipedia)