ok so ive been listening to some HF conversations and i keep hearing and seeing things like QSL, QRM, QSY, 73, and a bunch of other stuff i dont really understand. i know 73 means best wishes or whatever but the rest im kinda lost on. is there like a standard list somewhere or do people just kind of pick them up over time? also some of the abbreviations dont even seem to be Q codes, like people say things like OM and YL and i have no idea if thats a Q thing or something else entirely. just trying to figure out how people are actually communicating because right now it sounds like a foreign language half the time

yeah the Q codes go way back to like the maritime and telegraph days, they were originally meant to be used across language barriers so everyone would understand them regardless of what country they were from. QRM is interference from other stations, QSB is signal fading, QSY means you're changing frequency, QTH is your location. there are dozens of them but honestly you only really hear maybe 15-20 of them regularly on the air and the rest you might never encounter outside of a test question.

the OM and YL stuff is separate though, OM is old man which is just how hams refer to any other male operator regardless of age, kind of a tradition, and YL is young lady which is used for any female operator. some people find that terminology a bit dated but its still very common especially on HF. 73 comes from the old telegraphers too, means best regards. 88 is another one which means love and kisses, usually said to YLs. if you can find an old ARRL handbook or even just google ARRL Q code list you'll get a pretty complete reference, but honestly you just pick most of it up by listening for a few weeks

i was in the exact same spot not too long ago honestly. the one that confused me forever was QRN because i kept mixing it up with QRM, QRM is man made interference like other signals bleeding in and QRN is natural stuff like static from lightning and weather. took me embarassingly long to keep those two straight lol. also hear PSE a lot which is just please and TU is thank you, those arent Q codes just abbreviations people use specially on CW but they bleed over into phone sometimes too