The description of additional police services shall show and describe existing police services and proposed additional police services. The description shall be sufficient if it shows or describes the general nature and extent of the services. If the assessment district is divided into zones, the description shall indicate the class and type of additional police services to be provided for each such zone. The description may be prepared as a separate instrument or either or both may be incorporated in the diagram as a combined instrument. (Prior code § 83.04.430)