A nonconforming sign shall be any sign which:

A. Was lawfully maintained on the effective date of the ordinance from which the provisions of this title concerning nonconformity derive and had been lawfully erected in accordance with the provisions of any prior zoning ordinance but which sign does not conform to the limitations established by this title in the district in which the sign is located; or

B. Was lawfully maintained and erected on or after the effective date of the ordinance from which the provisions of this title concerning nonconformity derive in accordance with the provisions of this title but which sign, by reason of amendment to this title, after the effective date of said ordinance, does not conform to the limitations established by the amendment in the district in which the sign is located. (Ord. 1990-12 § 4: prior code § 5-2-5(S)(3)(m)(ii))