For uses not listed, the Administrator shall attempt to determine if the requested use is similar to a listed use in the subject zoning district. If the Administrator determines that the use is not similar to a listed use it is assumed that the use is not permitted in the subject district. In case of uncertainty, the Administrator may refer the request for clarification or classification to the Board of Zoning Appeals (BZA) for consideration in accordance with the provisions of uses not listed under the duties of the Board of Zoning Appeals.