Ah, the internet is such an amazing place! If you're patient, and are willing to look around, take the time to do some searching in some of the odd corners of what's available or, for that matter, utilize the web bot search power of some of the big companies like Google and carefully review what they find for you, you can run across some interesting stuff.
In this case, the item found (it's a .pdf which is located on-line at www.uscg.mil/directives/cim/5000-5999/CIM_5200_14A.pdf) is a manual, U.S. Coast Guard Heraldry, whose stated purpose is to define "the official U.S. Coast Guard Seal, Emblem, Mark, Signature, Color, and Ensign, as well as the Coast Guard Auxiliary Seal, Emblem, Mark, Signature, Ensign, and Patrol Ensign." So it covers not only the coat of arms United States Coast Guard (now a division of the U.S. Department of Homeland Security), below, in sometimes excruciating detail, but also flags, ensigns, colors, unit emblems, and auxiliary heraldry.
5 months ago