17 C.F.R. § 300.100 : Commodity and Securities Exchanges — SECURITIES AND EXCHANGE COMMISSION — RULES OF THE SECURITIES INVESTOR PROTECTION CORPORATION —ACCOUNTS OF "SEPARATE" CUSTOMERS OF SIPC MEMBERS — General

(a) For the purpose of sections 9(a)(2) and 16(12) of the Securities Investor Protection Act (hereinafter referred to as "the Act"), these rules will be applied in determining what accounts held by a person with a member of SIPC (hereinafter called a "member") are to be deemed accounts held in a capacity other than his individual capacity.
(b) Accounts held by a customer in different capacities, as specified by these rules, shall be deemed to be accounts of "separate" customers.
(c) A "person" as used in these rules includes, but is not limited to, an individual, a corporation, a partnership, an association, a joint stock company, a trust, an unincorporated organization, or a government or political subdivision thereof.
(d) The burden shall be upon the customer to establish each capacity in which he claims to hold accounts separate from his individual capacity.

17 C.F.R. §300.100