The following is Chapter 1 of TM 1-1510-224-10. That’s the Technical Manual for the RC-12P and RC-12Q, the Beechcraft RC-12 Guardrail, an airborne signals intelligence (SIGINT) collection platform based on the Beechcraft King Air and Super King Air.
Chapter 1 (below) contains the definitions for Warnings, Cautions, and Notes. Their use began in the military, aboard ships, aircraft, tanks, jeeps, trucks, and tractor-trailer rigs, as well as with artillary, mortars, cranes, and just about any other mechanical contrivance or piece of equipment. They’ve long since made their way into private industry, including IT and even business procedures. I see great value in using them in all manner of technical communications as they’re common enough most people are at least somewhat familiar with their use and they do a very good job highlighting, differentiating, and prioritizing key pieces of information in a way that helps human beings to avoid crossing certain lines which can be hazardous to their health and welfare, the safety and security of expensive equipment, as well as the smooth operation of any military or civilian endeavor.