D.C. Code § 36-127: Rights of former registrants preserved.

All persons who prior to July 3, 1926, registered any milk bottles, cans, crates, or other containers in accordance with the laws existing at the time of said registration shall be exempted from filing a new description in accordance with the terms of this subchapter and shall be entitled to the rights and benefits accruing under this subchapter in the same manner as if said registration was made in accordance with this subchapter; provided, that a copy of said registration duly certified by the Clerk of the United States District Court for the District of Columbia was within 30 days from and after July 3, 1926, filed in the Health Office of the District of Columbia.