The National Mediation Board (NMB)—the agency authorized by the Railway Labor Act at 45 U.S.C. § 151, et seq., to interpret various provision of that Act—issued its Final Rule addressing the selection of a representative of a carrier’s employees. The new rule, which takes effect on June 10, 2010, allows the NMB to certify the authorized representative of a craft or class of a carrier’s employees based on a majority of valid ballots cast in an election. The old rule requires the affirmative vote of a majority of all eligible voters in a class or craft in order for such an election to be valid. The rule applies once a dispute has arisen as to who may represent the employees and one or more parties to the dispute have requested that the NMB investigate the dispute and certify the representative. The rule does not revise the requirements at 29 C.F.R. 1206.2 to initially establish the existence of a representation dispute. The Final Rule amends the NMB’s regulations at Sections 1202.4 and 1206.4 of 29 C.F.R.