The district may be described by:
(a) Stating its exterior boundaries; or
(b) Giving a description thereof according to any official or recorded map; or
(c) Referring to a plat or map on file in the office of the clerk or engineer at the time of passing the resolution of intention, which shall indicate by a boundary line the extent of the territory included in the proposed district, and shall govern for all details as to the extent of the assessment district.
(Amended by Stats. 1950, 1st Ex. Sess., Ch. 65.)