District of Columbia Code
Part A - Board of Directors
§ 29–406.07. Resignation of directors

(a) A director may resign at any time by delivering a signed notice in the form of a record to the chair of the board of directors or to an executive officer or the secretary of the corporation.
(b) A resignation shall be effective when the notice is delivered unless the notice specifies a later effective time.
(July 2, 2011, D.C. Law 18-378, § 2, 58 DCR 1720.)
This section is referenced in § 29-401.50 and § 29-406.10.