iykyk
exclusive, knowing
the one-line answer
If you know you know. A signal that only insiders will understand.
IYKYK means this is for the people who already understand. You are not going to explain it. If you are in on it, you know. If you are not, that is also fine. Often used to reference niche communities or inside jokes..
mainstream
Your coworker might use this word.
01 / in the wild
hear it move.
insider
the Thursday night crowd... iykyk.
People who have been part of that scene will understand without explanation.