the.com/loophole
A rule's escape hatch, fully legal, infuriatingly intentional, and always found by someone richer than you.
means An ambiguity or omission in a law or contract that lets you sidestep its intent without breaking it.
from From medieval castle walls: a loop was a narrow slit archers shot through and slipped away by, an opening built into something solid.
Literal slitOriginally an arrow-firing gap in fortress walls.
Legal not illegalExploits the letter while dodging the spirit.
Tax favoriteEntire accounting careers built on finding them.