I worked with some sales people in a pre-sales role. This came up during prep for a presentation. A couple of us were on the command line on the projector. There was the usual chatter about getting the magic incantations right, and how come nothing is fully spelled out, etc...
Two of the women on the team brought up middle school notes and how they would often leave a lot out.
When people are familiar, there is a shared mini culture in play. Slang, common expression.
They would use first letters only, with the odd fully spelled out words here and there. Sort of a game, how well do you know your friends?
"Haven't you ever done that?"
"Of course not."
"Yeah, boys."
"It's fun"
And of course we started to play this silly game at work.
NH!
BRT
TY
YAW
YATB!
Soon, paragraphs became sentences.
Turns out a whole lot can be said this way and how well it is received is a direct function of how closely anyone reading are to the people exchanging the messages.
And it worked. Anyone playing got a lot closer to others also playing.
A fun friendship lark.
All that *nix stuff works the same way. Culture, familiarity...
Never thought about it that way myself, until that workplace word play happened.
The same sort of mapping to meaning seems to happen with shortened commands. It is all just lean in a way that means less work for basically the same outcome.
I find the move to make one space after a period equally funny, BTW.
Every time I abbreviate something on mobile, I see the next character after a space go to capitalized mode and wonder how anyone expected the parser to differentiate that from end of sentence.