; and (5) by adding at the end the following new subsection: (e) Annual report Not later than December 31 of each year, the Secretary of Defense shall submit to the congressional defense committees a report on the assistance provided under this section during the preceding fiscal year. . (b) Table of sections amendment The table of sections at the beginning of chapter 20 of title 10, United States Code, is amended by striking the item relating to section 408 and inserting the following new item: 408. Assistance in support of Department of Defense accounting for missing United States Government personnel. . 1045. Implementation of arrangements to build transparency, confidence, and security Section 2241 of title 10, United States Code, is amended by adding at the end the following new subsection: (d) Implementation of Vienna Document 2011 Amounts appropriated for operation and maintenance may be used by the Secretary of Defense for travel, transportation, and subsistence expenses for meetings and demonstrations hosted by the Department of Defense for the implementation of the Vienna Document 2011 on Confidence and Security-Building Measures. . 1046. Access to and use of military post offices by United States citizens employed overseas by the North Atlantic Treaty Organization who perform functions in support of military operations of the Armed Forces (a) Requirement to authorize use of post office Section 406 of title 39, United States Code, is amended by striking may authorize the use and inserting shall authorize the use . (b) Briefing requirement Not later than March 1, 2024, the Secretary of Defense shall brief the Committees on Armed Services of the Senate and House of Representatives on the revision of the Financial Management Regulation to authorize individuals under subparagraph (A) of section 406(c)(1) of title 39, United States Code, as amended by subsection (a), to utilize the authority provided under such subparagraph. If there is a determination that this authority is not feasible for a legal or