According to 32 USCS § 101 (6), the term Air National Guard means "that part of the organized militia of the several States and Territories, Puerto Rico, and the District of Columbia, active and inactive, that--
(A) is an air force;
(B) is trained, and has its officers appointed, under the sixteenth clause of section 8, article I, of the Constitution [USCS Constitution, Art I, § 8, cl 16];
(C) is organized, armed, and equipped wholly or partly at Federal expense; and
(D) is federally recognized."
According to 10 USCS § 101 (Title 10, Armed Forces; Subtitle A, General Military Law; Part I, Organization And General Military Powers; Chapter 1, Definitions), the term "Air National Guard of the United States" means “the reserve component of the Air Force all of whose members are members of the Air National Guard.” (10 USCS § 101)