(735 ILCS 5/2-205.1) (from Ch. 110, par. 2-205.1)
    Sec. 2-205.1. Service on voluntary unincorporated associations. A voluntary unincorporated association sued in its own name may be served by leaving a copy of the process with any officer of the association personally or by leaving a copy of the process at the office of the association with an agent of the association. A voluntary unincorporated association sued in its own name may also be notified by publication and mail in like manner and with like effect as individuals.
(Source: P.A. 83-901.)