5 U.S. Code § 4110
5.U.S. Code § 4110 is about Expenses of attendance at meetings. It is under Part 3 (Employees) Subpart C (Employee Performance) Chapter 41 (Training) of Title 5 (Government Organizations and Employees) of the Code.
Appropriations available to an agency for travel expenses are available for expenses of attendance at meetings which are concerned with the functions or activities for which the appropriation is made or which will contribute to improved conduct, supervision, or management of the functions or activities.