3 U.S. Code § 303
3 U.S. Code § 303 is about Definitions. It is under Chapter 4 (Delegation Of Functions) of Title 3 (The President) of the Code.
As used in this chapter, the term “function” embraces any duty, power, responsibility, authority, or discretion vested in the President or other officer concerned, and the terms “perform” and “performance” may be construed to mean “exercise”.