20 CFR 204.4: Conditions which preclude an employment relation.

(a) An individual shall not have been on August 29, 1935, an employee by reason of an employment relation if, during the last payroll period in which he or she rendered service to an employer prior to that date, such service was rendered outside of the United States to an employer not conducting the principal part of its business in the United States.

(b) An individual may not acquire an employment relation solely by virtue of service to a local lodge or division of a railway labor organization.