The United States Supreme Court has held that a municipal ordinance that prohibits outdoor advertising signs but excepts certain types of commercial and non-commercial messages from its application violates the first amendment.
Metromedia, Inc. v. City of San Diego, 453 U.S. 490 (1981).
Thomas A. French,
Constitutional Law - First Amendment - Commercial and Non-Commercial Speech - Content-Based Regulation - Billboards,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol20/iss4/6