Miss. Code § 27-15-9
For the purpose of this chapter the municipalities of the state are hereby divided into seven classes, numbered from one (1) to seven (7), which classes shall be according to the population thereof, as follows:
Class No. 1 shall include all municipalities having a population of twenty-five thousand (25,000) inhabitants or more.
Class No. 2 shall include all municipalities having a population of fifteen thousand (15,000) inhabitants, and less than twenty-five thousand (25,000) inhabitants.
Class No. 3 shall include all municipalities having a population of ten thousand (10,000) inhabitants, and less than fifteen thousand (15,000) inhabitants.
Class No. 4 shall include all municipalities having a population of five thousand (5,000) inhabitants, and less than ten thousand (10,000) inhabitants.
Class No. 5 shall include all municipalities having a population of three thousand (3,000) inhabitants, and less than five thousand (5,000) inhabitants.
Class No. 6 shall include all municipalities having a population of one thousand (1,000) inhabitants, and less than three thousand (3,000) inhabitants.
Class No. 7 shall include all municipalities having a population of five hundred (500) inhabitants, and less than one thousand (1,000) inhabitants.
The term "elsewhere in the state" as used in this chapter shall include all municipalities having a population of less than five hundred (500) inhabitants, and all other places outside of any municipality.
Miss. Code § 27-15-9