District of Columbia Code
Part B - Meetings and Action of the Board
§ 29–306.23. Waiver of notice

(a) A director may waive any notice required by this chapter, the articles of incorporation, or bylaws before or after the date and time stated in the notice. Except as otherwise provided in subsection (b) of this section, the waiver shall be in writing, signed by the director entitled to the notice, and filed with the minutes or corporate records.
(b) A director’s attendance at or participation in a meeting waives any required notice to the director of the meeting unless the director at the beginning of the meeting, or promptly upon arrival, objects to holding the meeting or transacting business at the meeting and does not thereafter vote for or assent to action taken at the meeting.
(July 2, 2011, D.C. Law 18-378, § 2, 58 DCR 1720.)