N.H. Rev. Stat. Ann. § 31:128

A certified copy of the municipal legislation, or a certified code, codification or compilation which includes the legislation, shall constitute prima facie evidence that the legislation was enacted on or prior to the date of certification. Certification shall be by the town or city clerk, or by the official enacting the legislation, or by the chairman, secretary or clerk of the board or body enacting the municipal legislation. The copy or code shall specify, by name or title, which officer, board or body of the municipality enacted the legislation. This method of proving municipal legislation shall not be exclusive.