This guide was developed by the United States Department of Transportation and Nuclear Regulatory Commission, and the Canadian Nuclear Safety Commission to provide direction on the standard format and content for applications for approval of packages used to transport Type B(U) and fissile materials. The guide is designed to facilitate the United States validation of Competent Authority approvals for export/import purposes and limit redundant technical reviews. A companion guide document has been developed and published in Canada as RD-364, "Joint Canada - United States Guide for Approval of Type B(U) and Fissile Material Transportation Packages."