The Code of Practice for Determining Employment or Self-employment Status of Individuals (pdf) contains criteria which can be used to clarify whether a person is employed or self-employed. In most cases, it is clear whether a person is an employee or not.
The 708 area code belongs to the state of Illinois (IL) and some of the locations covered are Cicero, Oak Park and more:
area code 678 was put into service area code 678 is an overlay of area codes 404 and 770 in 2010 area code 678 was overlaid with area code 470 this resulted in an area code overlay complex of 404 470 678 and 770