Indiana Code Title 27. Insurance § 27-14.5-1-5

(1) a knowing participation in a joint activity whether or not under an express agreement;

(2) interdependent conscious parallel action toward a common goal under an express agreement or otherwise;  or

(3) a combination or pooling of voting interests or other interests in the securities of any person for a common purpose under any contract, understanding, relationship, agreement, or other arrangement, written or otherwise.

(1) its trustee;  or

(2) a person who serves in a capacity similar to a trustee;