This document reviews the legal standards providing differential treatment of “public vessel” under federal regulations, including regulatory definitions of that term. In addition, it reviews language in key international legal instruments that provide similar special treatment for selected vessels owned by governments. This document is a supplement to Status of the U.S. Academic Research Fleet as Public Vessels under U.S. and International Law, which discusses the application of these and other legal authorities relevant to a determination of whether U.S. academic research fleet vessels are public vessels. The authorities presented here are separated by issuing agency (for regulatory citations). International authorities are presented separately. This document is to be used for research purposes only and is not legal advice