Not the "no shoes indoors type", the quirky ones unique to your personalities.
In this house for example, you have to give an "Advanced Crisp Warning", or ACW.
The rule is that, although either party in the household is permitted to partake of the naice crisps whenever he or she chooses, they must give the other party an ACW if they finish the last bag in the house, as we both agree that the sense of crushing disappointment felt when one fancies and then subsequently discovers they cannot have naice crisps is something we don't want to inflict on one another.
We also have Dog Jingles, which are short bursts of song which have to be sung in the car when you spot a particular breed of dog (the jingle describes the characteristics of the breed - Golden Retrievers for example: "Just...So...Happy...To...BE HERE!" sung to jaunty "Taa-daa!" type tune).
Hit me with yours.