29 C.F.R. § 101.26
The investigation of the question as to whether the authority of a labor organization to make an agreement requiring membership in a labor organization as a condition of employment is to be rescinded is initiated by the filing of a petition by an employee or group of employees on behalf of 30 percent or more of the employees in a bargaining unit covered by an agreement between their employer and a labor organization requiring membership in such labor organization. The petition must be in writing and signed, and either must be notarized or must contain a declaration by the person signing it, under the penalties of the Criminal Code, that its contents are true and correct to the best of his knowledge and belief. It is filed with the regional director for the Region in which the alleged appropriate bargaining unit exists or, if the bargaining unit exists in two or more Regions, with the regional director for any of such Regions. The blank form, which is supplied by the Regional Office upon request or is available online, provides, among other things, for a description of the bargaining unit covered by the agreement, the approximate number of employees involved, the names of any other labor organizations which claim to represent the employees, the petitioner's position on the type, date(s), time(s), and location(s) of the election sought, and the name of, and contact information for, the individual who will serve as the petitioner's representative. The petition may be filed by facsimile or electronically. The petitioner must supply with the petition evidence of authorization from the employees.
29 C.F.R. §101.26