§ 321. Certificates of service. 1. In any proceeding under this act a
certificate executed by an officer of the applicable force of the armed
forces of the United States or by an officer of the applicable force of
the organized militia shall, when produced, be prima facie evidence of
the facts therein certified and of the authority of the signer to issue
the same.

2. When a person in military service has been reported missing he
shall be presumed to continue in such service until accounted for, and
no period herein limited which begins or ends with the death of such
person shall begin or end until the death of such person is in fact
reported to or proved by the applicable force of the armed forces of the
United States or of the organized militia, or until such death is proved
by a court of competent jurisdiction; provided, that no period herein
limited which begins or ends with the death of such person shall be
extended beyond a period of six months after the time when this act
ceases to be in force.