In the RR Riverfront Redevelopment Overlay Zone, signs shall meet the requirements that apply in the C-C District, except that the Planning Commission may approve modifications to sign provisions under the PRD provisions, in response to a written request from the applicant. In no case shall more than one freestanding sign be allowed per building per street frontage. In addition, a professional sports stadium may also include one 200 square feet freestanding sign with up to two sides. Signs that are not readable from a street and from beyond the property line are not regulated by this section.