Mo. Rev. Stat. § 3.050
The committee may prefix to the statutory law a table of contents and shall prepare suitable headnotes or catch words to indicate briefly the subject matter of the several sections. The sections shall be numbered in such sequence as to permit insertion of additional legislation without changing the numbers. Notes shall be inserted to indicate the source of the various sections. The committee shall classify and arrange the entire body of statute laws in a logical order throughout the volumes, the arrangement to be such as will enable subjects of a kindred nature to be placed under one general head with necessary cross references. Notes of decisions of the courts, historical references and other material included in editions of the revised statutes of Missouri and supplements or pocket parts thereto shall be arranged in such manner as the committee finds will promote the usefulness thereof.
§ 3.050, RSMo