if you know, you know

phrase1

1. •
   (informal, humorous) Used to signify a reference or allusion to something that is only understood by certain groups of people.

   • “They’re very if you know, you know,” says Sam Millen-Cramer, a 28-year-old marketing specialist, who wears his £15 Mountain Warehouse zip-up with baggy pants from Margaret Howell […] — 2023