So, the only AR platform rifles every designed and intended for military use were the select fire (fully auto) versions. The semi-auto version was designed and intended for civilian use. So, the AR-15 (as opposed to the M-16 and M-4) was not a military rifle and was designed and manufactured for civilians.
“So, the only AR platform rifles every designed and intended for military use were the select fire ... the AR-15 ... was designed and manufactured for civilians.”
Still wrong.
“AR-15” as a designator has been used more than once, by different organizations, for different items, at different times, intended for different markets.
ArmaLite (the original firm) used “AR” followed by numerics to designate different firearms; “AR-15” was just one. They developed sporting shotguns and rifles, in addition to military rifles. They also created specialized firearms that do not fit either category perfectly: the AR-7 lightweight rifle that could be broken down and stored inside its own buttstock was initially aimed at DoD, for downed aircrews in survival situations. It was chambered in 22LR. The military ultimately declined it, but it enjoyed some sales success in the civilian world.
Today’s ArmaLite firm arose from a “re-launch” in the 1990s. The modern founders purchased material assets, patents, and intellectual properties that had been created by the original company, and began producing arms - old designs and new. They’ve leaned heavily on the original firm’s accomplishments and legacy, even as they’ve innovated. On their official website (armalite.com) they point out that they introduced their M-15 rifles to compete with Colt’s “trademarked AR-15.”