D.C. Code § 29-405.40: Voting agreements.

(a)

Two or more members may provide for the manner in which they will vote by signing an agreement in the form of a record for that purpose. A voting agreement shall be valid for a period of up to 10 years. If no time is stated in the voting agreement, the agreement shall be valid for 5 years. The members who signed the voting agreement may, at any time, alter or terminate the agreement by signing a new agreement.

(b)

A voting agreement created under this section shall be specifically enforceable, except that a voting agreement is not enforceable to the extent that enforcement of the agreement would violate the purposes of the membership corporation.