dog whistle

noun3

1. •
   A high-pitched whistle, generally inaudible to humans, used to train dogs.
2. •
   A political allusion or comment that only a certain audience is intended to note and recognize the significance of; particularly in relation to controversial or extreme viewpoints.

   • Putting “globalist” in quotes suggests a jest or in-joke of sorts, so it’s at least possible this wasn’t intended as some kind of anti-Semitic dog whistle. — 2018
3. •
   (figurative) That which is understood only by a narrow demographic.