17 CFR 300.102: Accounts held by executors, administrators, guardians, etc.

(a) Accounts held with a member in the name of a decedent or in the name of his estate or in the name of the executor or administrator of the estate of the decedent shall be combined so as to constitute a single account of a separate customer.

(b) An account held with a member by a guardian, custodian, or conservator for the benefit of a ward or for the benefit of a minor under the Uniform Gifts to Minors Act or in a similar capacity shall be deemed to be held by such guardian, custodian, or conservator in a different capacity from any account or accounts maintained by such person in his individual capacity.