GenZ kids use Instagram where there’s no character limit, so their acronyms are ornamental and aimed at being unintelligible to their parents. Whereas I cut my social media teeth on Twitter, which has character limits, so Twitterati’s acronyms are utilitarian and driven by a basic need.
IIRC: If I Recall Correctly. “As far as I remember”.
AFAIK: As Far As I Know.
IYKYK: If You Know You Know. Less about information and more about insider signaling. Inside information / joke.
H/T. Hat Tip. Similar to “Courtesy of”.
F2F: Face To Face. Physical world, not digital / virtual.
IMO: In My Opinion.
FYI: For Your Information.
JFYI: Just For Your Information.
SMH: Shake My Head.
NGMI: Not Gonna Make It. You’ll get rekt.
TIL: Today I Learned. Interesting fact that I learned recently.
PSA: Public Service Announcement.