1. The following identified as a shareholder in a corporation's current record of shareholders constitutes one shareholder:
a. Three or fewer co-owners;
b. A corporation, partnership, trust, estate, or other entity;
c. The trustees, guardians, custodians, or other fiduciaries of a single trust, estate, or account; or d. One data address.
2. Shareholdings registered in substantially similar names constitute one shareholder if it is reasonable to believe the names represent the same person.