5-4-301. Bills received by governor -- how endorsed. Each bill passed by the legislature, except bills proposing amendments to the Montana constitution, bills ratifying proposed amendments to the United States constitution, resolutions, and initiative and referendum measures, must be submitted to the governor for the governor's signature. Each bill must, as soon as it is delivered to the governor, be endorsed as follows: "This bill was received by the governor this .... day of ...., 20...". The endorsement must be signed by the governor or by an assistant authorized by the governor.