Names are mutable, but things are immutable. A name may be true or false, or may change, but the thing itself always maintains its identity.

Explanation

(English-origin maxim.) Labels change; substance does not. A thing is what it is regardless of the name applied to it — renaming a tax as a fee, or a right as a privilege, does not alter its true nature.

Where this applies

• A contract is labeled a 'lease' but functions as a sale, and a court looks past the name to the substance.
• A fee is relabeled a 'tax' to avoid a legal limit, but its true nature controls.