Mo. Rev. Stat. § 142.938

Each terminal operator in this state and every supplier licensed by this state for the collection of tax on motor fuel shall cause terminal-issued shipping papers to meet such tamper-resistant standards as the director may by regulation require including, but not limited to messages which identify whether shipping papers have been photocopied, numbering systems, nonreproducible coding and other devices. However, the director may not make any such regulations effective earlier than twenty-four months after the promulgation of a final regulation imposing the requirements.