29 C.F.R. § 452.71

(a) Each bona fide candidate for office has a right, once within 30 days prior to any election in which he is a candidate, to inspect a list containing the names and last known addresses of all members of the labor organization who are subject to a collective bargaining agreement requiring membership therein as a condition of employment. The right of inspection does not include the right to copy the list but does include the right to compare it with a personal list of members. It is the intent of the Act that such membership lists be made available for inspection at the candidates' option any time within the 30-day period. The list is not required to be maintained continuously and may be compiled immediately before each election. The form in which the list is to be maintained is not specified by the Act. Thus, a card index system may satisfy the requirements of the Act. The list may be organized alphabetically or geographically, or by local in a national or international labor organization.

(b) It is the duty of the labor organization and its officers to refrain from discrimination in favor of or against any candidate with respect to the use of lists of members. Thus, if a union permits any candidate to use such lists in any way other than the right of inspection granted by the Act, it must inform all candidates of the availability of the list for that purpose and accord the same privilege to all candidates who request it. Such privileges may include permitting inspection of the list where members are not subject to a collective bargaining agreement requiring membership as a condition of employment, inspecting the list more than once, or copying the list.