Treas. Reg. § 1.501(c)(7)-1

(a) The exemption provided by section 501(a) for organizations described in section 501(c)(7) applies only to clubs which are organized and operated exclusively for pleasure, recreation, and other nonprofitable purposes, but does not apply to any club if any part of its net earnings inures to the benefit of any private shareholder. In general, this exemption extends to social and recreation clubs which are supported solely by membership fees, dues, and assessments. However, a club otherwise entitled to exemption will not be disqualified because it raises revenue from members through the use of club facilities or in connection with club activities.

(b) A club which engages in business, such as making its social and recreational facilities available to the general public or by selling real estate, timber, or other products, is not organized and operated exclusively for pleasure, recreation, and other nonprofitable purposes, and is not exempt under section 501(a). Solicitation by advertisement or otherwise for public patronage of its facilities is prima facie evidence that the club is engaging in business and is not being operated exclusively for pleasure, recreation, or social purposes. However, an incidental sale of property will not deprive a club of its exemption.