Regular meetings of the Commission, open to the public, are held monthly on the third Thursday of the month, beginning at 10 a.m., at its offices in Suite 312, 441 F Street, N.W. Washington, D.C. 20001, except that by action of the Commission a regular meeting in any particular month may be omitted or it may be held on another day or at a different time or place. A special meeting, open to the public, may be held in the interval between regular meetings upon call of the Chairman and five days' written notice of the time and place mailed to each member who does not in writing waive such notice. On all matters of official business, the Commission shall conduct its deliberations and reach its conclusions at such open meetings except as stated in § 2101.12 provided, however, the Commission members may receive staff briefings or may have informal background discussions among themselves and the staff outside of such meetings.