a . Used by doctors, dentists, lawyers, accountants, or other duly licensed professionals and formed much the same as ordinary business corporations.
b. Formed to administer a unit of government (cities, towns) or created by the government to conduct public business (TVA, postal service).
c. Usually private corporations, operate not for profit, dividends not paid, follow corporation statutes (state), individual members not personally liable. These corporations may make a profit, but it may not be distributed to its members, directors, or officers; the profit must be used for the charitable, educational, or scientific purposes for which the corporations were formed.