17 CFR § 166.1 - Definitions.
(a) The term Commission registrant as used in this part means any person who is registered or required to be registered with the Commission pursuant to the Act or any rule, regulation, or order thereunder.
(b) [Reserved]
(c) The term customer as used in this part means any person trading, intending to trade, or receiving or seeking advice concerning any commodity interest, including any existing or prospective client or subscriber of a commodity trading advisor or existing or prospective participant in a commodity pool, but the term does not include a person who is acting in the capacity of a Commission registrant with respect to the trade.
(d) The term commodity account as used in this part means the account of a customer in which any commodity interest is, or is intended to be, traded.