Texting shorthand.
The small letters doing a lot of work.
FR
“For real”: an emphasis on sincerity, a strong agreement, or a surprised question meaning “seriously?”
Casual · sincere or questioningIn context
IYKYK
“If you know, you know”: a signal that people with the shared experience or background will understand an unstated reference.
Knowing · inside referenceIn context
POV
“Point of view.” In captions, it usually introduces a situation the viewer is invited to imagine experiencing.
Perspective · scenario framingIn context
TL;DR
“Too long; didn’t read.” It can dismiss a long message, but is also a common label for a short summary supplied by the writer.
Concise · sometimes dismissiveIn context