"Military personnel might use "86" to refer to scrapping equipment (e.g., "That old radio got 86'd") or ending a plan or mission (e.g., "The op was 86'd due to bad weather"). It's not an official term in military doctrine or manuals, but it's part of the informal jargon and culture of soldiers, sailors, and airmen due to its common and frequent use, and is a concept military members are assumed to understand, although it originates in broader civilian language."
Eighty-six is slang meaning "to throw out," "to get rid of," or "to refuse service to." It comes from 1930s soda-counter slang meaning that an item was sold out. There is varying anecdotal evidence about why the term eighty-six was used, but the most common theory is that it is rhyming slang for nix.https://www.merriam-webster.com/wordplay/eighty-six-meaning-origin
https://en.m.wikipedia.org/wiki/86_(term)
"Military personnel might use "86" to refer to scrapping equipment (e.g., "That old radio got 86'd") or ending a plan or mission (e.g., "The op was 86'd due to bad weather"). It's not an official term in military doctrine or manuals, but it's part of the informal jargon and culture of soldiers, sailors, and airmen due to its common and frequent use, and is a concept military members are assumed to understand, although it originates in broader civilian language."
https://www.merriam-webster.com/wordplay/eighty-six-meaning-origin
Eighty-six is slang meaning "to throw out," "to get rid of," or "to refuse service to." It comes from 1930s soda-counter slang meaning that an item was sold out. There is varying anecdotal evidence about why the term eighty-six was used, but the most common theory is that it is rhyming slang for nix.https://www.merriam-webster.com/wordplay/eighty-six-meaning-origin
Words can change meanings. Language is fluid.