Wis. Stat. § 185.15: Notice to members, stockholders or other persons; waiver.

(1) Whenever notice is required by this chapter to be given to any person, the notice shall be given either personally or by mail. If mailed, the notice is given when it is deposited or a newsletter or other publication of a cooperative or of an affiliated organization which includes the notice is deposited in the United States mail, with postage prepaid thereon, addressed to such person at his or her address as it appears on the records of the cooperative.

(2) A signed waiver is equivalent to personal notice to the person so signing. The waiver may be signed at any time.