(i) In the case of a plan not maintained according to a collective bargaining agreement, including a plan maintained by a single employer with more than one establishment, a multiple employer plan, and a plan maintained by a controlled group of corporations (within the meaning of
section 1563(a) of the Internal Revenue Code of 1954 (the Code)), determined without regard to
section 1563(a)(4) and (e)(3)(C) of the Code), documents shall be made available for examination in the principal office of the employer and at each employer establishment in which at least 50 participants covered under a plan are customarily working. “Establishment” means a single physical location where business is conducted or where services or industrial operations are performed. Where employees are engaged in activities which are physically dispersed, such as agriculture, construction, transportation and communications, the “establishment” shall be the place to which employees report each day. When employees do not usually work at, or report to, a single establishment - for example, traveling salesmen, technicians, and engineers - the establishment shall be the location from which the employees customarily carry out their activities - for example the field office of an engineering firm servicing at least 50 participants covered under the plan.