so ive been licensed for about 4 months now and i notice pretty much everyone on HF uses the NATO phonetic alphabet when giving their callsign or spelling something out. my question is whether thats actually required or if its just kind of the accepted thing to do. like nobody ever told me i HAD to say Whiskey instead of just W but it feels like you're expected to. i tried using my own words once on a net and the net control asked me to repeat myself twice so maybe thats my answer lol. also is there like an official list or do people just know it from memory

not required by the FCC or anything like that, its just the standard that everyone settled on because it actually works. the whole point is that those specific words were chosen because they sound distinct from each other even over a bad signal or with heavy QRM. like November and November dont sound like anything else in the alphabet set, whereas if you just said N for Neon or whatever theres a good chance someone hears M. you'll pick up the whole alphabet pretty fast just from being on the air, i think i had it memorized within a few weeks without even trying. some guys especially the older timers will occasionally use non-standard ones but its usually obvious what they mean

yeah the net control thing is basically your answer right there. when propagation is rough or theres noise people really do struggle to copy individual letters and having those specific words just cuts through better. i still mess up occasionally and say something random like Victor for V when im tired but mostly muscle memory kicks in. theres a printable reference card on the ARRL site if you want something to stick near the radio while youre still learning it