The mailbox rule is a legal principle that states that an acceptance of an offer is effective when it is placed in the mailbox, regardless of when it is received by the offeror.

The plurality rule is a voting system where the candidate with the most votes wins.

The cube rule states that when you double the dimensions of a shape, its volume increases by a factor of eight.

The platinum rule is a principle that encourages treating others the way they want to be treated.

I found a box full of sliding-rules in the attic.

He used a sliding-rule to calculate complex mathematical equations.

Rapoport's rule states that species at higher latitudes have broader geographic ranges than species at lower latitudes.

The employees decided to go on work to rules.

I always carry a plumb rule in my toolbox.

The plumb rules are essential tools for ensuring vertical alignment in construction.