In politics, a dog whistle is the use of coded or suggestive language in political messaging to garner support from a particular group without provoking opposition. The concept is named after ultrasonic dog whistles, which are audible to dogs but not humans. Dog whistles use language that appears normal to the majority but communicates specific things to intended audiences. They are generally used to convey messages on issues likely to provoke controversy without attracting negative attention.

https://en.wikipedia.org/wiki/Dog_whistle_(politics)