Miss. Code § 23-15-521
Before counting the ballots, the election commissioners, or their designees, shall have the OMR equipment tested to ascertain that it will accurately count the votes cast for all offices and on all measures. Representatives of the political parties, candidates, the press and the general public may witness the test conducted on the OMR equipment. The test shall be conducted by processing a preaudited group of ballots so marked as to record a predetermined number of valid votes for each candidate and on each measure, and shall include for each office one or more ballots that have votes in excess of the number allowed by law in order to test the ability of the OMR equipment to reject such votes. If any error is detected, the cause of the error shall be ascertained and corrected and an errorless count shall be made and certified to by the officials in charge before the count is started. On completion of the count, the programs, test materials and ballots shall be sealed and retained as provided for paper ballots.
Miss. Code § 23-15-521