For the purpose of this chapter and the building numbering system adopted by this chapter, the city shall be divided into the following 4 areas:
A. Northeast: North of Southern Pacific Company right-of-way and east of Ivy Street.
B. Northwest: North of Southern Pacific Company right-of-way and west of Ivy Street.
C. Southeast: South of Southern Pacific Company right-of-way and east of Ivy Street.
D. Southwest: South of Southern Pacific Company right-of-way and west of Ivy Street.