18 CFR § 358.3
Affiliate of a specified entity means:
(1) Another person that controls, is controlled by or is under common control with, the specified entity. An affiliate includes a division of the specified entity that operates as a functional unit.
(2) For any exempt wholesale generator (as defined under § 366.1 of this chapter), affiliate shall have the meaning set forth in § 366.1 of this chapter, or any successor provision.
(3) “Control” as used in this definition means the direct or indirect authority, whether acting alone or in conjunction with others, to direct or cause to direct the management policies of an entity. A voting interest of 10 percent or more creates a rebuttable presumption of control.