§ 5703.
Per diem, travel, and transportation expenses; experts and consultants; individuals serving without pay
An employee serving intermittently in the Government service as an expert or consultant and paid on a daily when-actually-employed basis, or serving without pay or at $1 a year, may be allowed travel or transportation expenses, under this subchapter, while away from his home or regular place of business and at the place of employment or service.
([Pub. L. 89–554], Sept. 6, 1966, [80 Stat. 499]; [Pub. L. 91–114, § 2], Nov. 10, 1969, [83 Stat. 190]; [Pub. L. 94–22, § 4], May 19, 1975, [89 Stat. 85].)