159.02   APPLICABILITY; EFFECT.
A sign may be erected, placed, established, painted, created or maintained in the City only in conformance with the standards, procedures, exemptions and other requirements of this chapter. The effect of this chapter as more specifically set forth herein is:
1.   To establish a permit system to allow a variety of types of signs in commercial and industrial zones, and a limited variety of signs in other zones, subject to the standards and permit procedures of this chapter;   
2.   To allow certain signs that are small, unobstructive, and incidental to the principal use of respective lots on which they are located, subject to the substantive requirements of this chapter, but without a requirement for permits;   
3.   To provide for temporary signs without commercial messages in limited circumstances in the public right-of-way;   
4.   To prohibit all signs not expressly permitted by this chapter; and   
5.   To provide for the enforcement of the provisions of this chapter.