California Code, Civil Code - CIV § 6752

(a) Unless the governing documents provide otherwise, and regardless of whether the association is incorporated or unincorporated, the association may exercise the powers granted to a nonprofit mutual benefit corporation, as enumerated in Section 7140 of the Corporations Code, except that an unincorporated association may not adopt or use a corporate seal or issue membership certificates in accordance with Section 7313 of the Corporations Code.

(b) The association, whether incorporated or unincorporated, may exercise the powers granted to an association in this act.