Explanation of a “first set” of guidelines prepared by the WP.29 secretariat concerning the submission and adoption of modifications to UN Regulations, especially taking into consideration the pending Revision 3 to the 1958 Agreement which envisions, among other things, the acceptance to multiple “versions” of each regulation. This document covers: amendments resulting from draft Revision 3; publication of new series of amendments; long transitional provisions; versions of UN Regulations; use of cross-references; amendment commencement dates; consolidation of amendments to once per year; and use of “compilations” of modifications.