D.C. Mun. Regs. tit. 22, r. 22-B2012
Any notice required by this chapter may be served either personally or by certified mail, return receipt requested, directed to the applicant or licensee at the last known address as shown by the records of the Department.
If notice is served personally, it shall be considered by the Director to have been served at the time when delivery is made to the applicant or licensee.
If notice is served by certified mail, it shall be considered by the Director to have been served on the date written or stamped upon the return receipt showing delivery of the notice to the applicant or licensee, or refusal of the applicant or licensee to receive the notice.
In the event that the applicant or licensee is no longer at the last known address as shown by the records of the Department and no forwarding address is available, the notice shall be considered by the Director to have been served on the date the return receipt bearing the notification is received by him or her.
If an applicant or licensee scheduled for a hearing does not appear and no continuance has been or is granted, the Director may take the contemplated action without a hearing.
D.C. Mun. Regs. tit. 22, r. 22-B2012