The following persons are exempted from the requirements of Sections 753.04 and 753.05: Charitable solicitors, temporary businesses operated by and for tax exempt organizations, and any other persons otherwise exempted by law. The following additional persons shall be exempted from the requirements of this chapter: persons selling newspapers; commercial travelers or selling agents calling upon commercial establishments in the usual course of business, and real estate licensees. (1969 Code 110.06)