; and (B) (i) if the Secretary concurs with the recommendation, an action plan to implement the recommendation; or (ii) if the Secretary rejects the recommendation, a justification for such rejection. (i) Electronic tracking (1) In general The Ombudsman, in coordination with the Commissioner of U.S. Customs and Border Protection, the Director of U.S. Immigration and Customs Enforcement, and the Office of Refugee Resettlement of the Department of Health and Human Services, shall develop recommendations for the establishment of an electronic tracking number system on a single interface, which shall be used to track the location of a child who has been separated from a parent, legal guardian, or other relative of such child, and which shall be accessible to agents and officers of U.S. Customs and Border Protection, U.S. Immigration and Customs Enforcement, and the Office of Refugee Resettlement. (2) Tracking number The recommendations developed under this subsection shall consider how a tracking number can be assigned to a child who has been separated from a parent, legal guardian, or other relative of such child that— (A) is transferable; (B) may be shared easily on the electronic tracking system described in this subsection by agents and officers of— (i) U.S. Customs and Border Protection; (ii) U.S. Immigration and Customs Enforcement; and (iii) the Office of Refugee Resettlement of the Department of Health and Human Services