Mo. Rev. Stat. § 328.130
There shall be furnished to each person to whom a certificate of registration is issued a card or certificate certifying that the holder thereof is entitled to practice the occupation of barber in this state, and it shall be the duty of the holder of such card or certificate to post the same in a conspicuous place in front of his working chair where it may be readily seen by all persons whom he may serve.
(RSMo 1939 § 10135, A.L. 1981 S.B. 16)
Prior revisions: 1929 § 13530; 1919 § 12171; 1909 § 1188