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A subsection of the Internal Revenue Code governing the status of non-profit organizations devoted to business purposes. That is, a 501(c)5 organization seeks to promote better business conditions for persons or companies that belong to it. Examples of organizations that may register under subsection 501(c)6 include chambers of commerce and real estate boards. They may conduct lobbying for their causes, but not as their primary activity. 501(c)6 organizations are exempt from federal taxation.