301-10.106—When must I use a contract city-pair fare?
If you are a civilian employee of an agency as defined in § 301-1.1 of this chapter, you must always use a contract city-pair fare for scheduled air passenger transportation service unless one of the limited exceptions in § 301-10.107 exist. An Internet listing of contract city-pair fares is available at http://www.gsa.gov/citypairs.