Nolo's Plain-English Law Dictionary
A written statement issued by the President of the United States when signing a bill into federal law. The statement may address how the executive branch intends to interpret or enforce provisions of the new law. For example, a signing statement might declare that the president believes a part of the law is unconstitutional. The legal effect of signing statements is unclear. Use of signing statements that assert claims about the constitutionality of laws was condemned by an American Bar Association report in 2006.