All signs shall be kept in a neat, clean, and attractive condition. This includes the periodic cleaning, painting, repairing, and/or general maintenance of the sign. Maintenance shall also include the updating of the information provided by signs. All signs shall give an accurate representation of the current goods/prices offered, occupant, and/or other circumstances that are advertised on the sign. This maintenance shall be the responsibility of the holder of the sign permit. Any sign that is not properly maintained shall be deemed to be an illegal nonconforming use. (Ord. 523 §§ 1, 3(part), 1989)