By definition, record means "best" so that was my mistake in saying it was literal; however, now that I think of it, I have no idea where I got the definition. I thought Daniel Goodman had a video but it appears he did not. Maybe it's something I made up in a dream because it seems real to me that this was something.
the R on LR, NR, CR, WR etc = RECORD
which means the solve happened in a competiton as a RECORDed solve counting on the person's official WCA profile
I never made a video on this afaik, but I'm pretty sure Andrew Nathenson (ColorfulPockets) did - I can't find his video now but maybe someone else remembers. Pre-2017 or so, the terminology was:
PB - personal best (used for either your best official solve or your best unofficial solve, depending on context)
Overall PB - overall personal best (used for clarifying, when you get a competition result that's also your best solve ever)
WR - world record, best solve ever done in a competition
UWR - unofficial world record, best solve ever done outside a competition
These were somewhat confusing and inconsistent (PB often resulted in conversations like "I just got a PB!" "Nice, official or overall?") so Andrew (I think) proposed an R/B dichotomy to differentiate official results from other results:
PR/PB - personal record (official) and personal best (overall)
WR/WB - world record (official) and world's best (overall)
Once people started adopting this system around the late 2010s, PB became less ambiguous. UWR then became obsolete/archaic/deprecated (I like all those words to describe it and couldn't pick just one lol), but its meaning never
changed as far as I know, and it's still colloquially used pretty often as a synonym to WB.
While PB/PR is extremely useful because of the previous ambiguity of "PB", the WR/UWR terminology was never actually confusing -- it's just inconsistent after the introduction of PR and WB. That made it a lot harder to get the entire community to switch to WB when UWR really worked fine, so you'll still see some people use UWR as it used to be used.
But, the idea of UWR being understood by some to mean something different from WB is super linguistically interesting and I hadn't heard of that before! Words are only what we make them, so you're not necessarily
wrong but people might misunderstand you if that definition isn't widespread. (For my own sake I kinda hope it's not widespread because if it is then I've been misunderstanding a lot of people lol)