What do common acronyms like AITA, TIFU, TIL, ELI5, LPT, CMV, and TL;DR stand for?

These acronyms each originated in a specific subreddit before spreading across the broader platform as part of standard Reddit vocabulary. AITA stands for "Am I the Asshole," the name and central question of r/AmItheAsshole, where users describe interpersonal conflicts and ask the community to assign blame. The subreddit responds with verdict acronyms: NTA (Not the Asshole), YTA (You're the Asshole), ESH (Everyone Sucks Here), and NAH (No Assholes Here). The framework has become so well-recognized that people use "AITA" as shorthand even outside that subreddit to frame any moral dilemma. TIFU stands for "Today I Fucked Up," originating from r/tifu, where users confess embarrassing or disastrous mistakes they made. Despite the name implying the same day, posts frequently cover events from the past. TIL means "Today I Learned" and comes from r/todayilearned, a community dedicated to surprising factual discoveries. Like TIFU, the "today" is more rhetorical than literal. ELI5 stands for "Explain Like I'm Five," from r/explainlikeimfive, a community where complex subjects are broken down into plain, simple language accessible to a non-expert. LPT means "Life Pro Tip," from r/LifeProTips, used to share practical everyday advice. CMV stands for "Change My View," from r/changemyview, where a poster states an opinion and invites counterarguments, awarding a delta symbol to any reply that meaningfully shifts their thinking. TL;DR stands for "Too Long; Didn't Read." Properly used, a poster appends it at the bottom of a long text followed by a brief summary, allowing readers who want the condensed version to jump straight to it. Improperly, commenters sometimes post just "TL;DR" as a dismissive response to something they did not read, which is generally considered rude. Together these acronyms form a shared vocabulary that makes navigating Reddit faster and signals cultural fluency to the people you are conversing with.