IYKYK
IYKYK (phrase) means If you know, you know: used to mark something as an in-joke or shared reference that will land only with people already familiar with it. Example: “Third table from the back, 2019. IYKYK.”
How to use IYKYK
Learner’s notesIn plain EnglishA way of saying "only some people will get this, and that's the point."
Informal, almost entirely written rather than spoken.
Fill the gap
Can you complete this real example?
Third table from the back, 2019. _____.
Etymology
An initialism of the phrase "if you know, you know," which spread through social media captions and comments in the late 2010s.