Mo. Rev. Stat. § 217.475
217.475 Director of division of adult institutions to inform prisoner of the law in ...
217.475. Director of division of adult institutions to inform prisoner of the law in writing. — The director shall arrange for all offenders to be informed in writing of the provisions of sections 217.450 to 217.485 and for a record of such writing to be placed in the offender's file.
(L. 1982 H.B. 1196 § 83, A.L. 1983 H.B. 713 Revision, A.L. 1989 H.B. 408)