“Are they looking for a coded call to organize insurrection?”
They call them “dog whistles”.
For example, the tweeted phrase “Merry Christmas” is a dog whistle to his white supremacist supporters to go lynch black people.
This tweet was a dog whistle for “storm the capitol, stop the electoral count, and overthrow the government by force at once.”
“I am asking for everyone at the U.S. Capitol to remain peaceful. No violence! Remember, WE are the Party of Law & Order – respect the Law and our great men and women in Blue. Thank you!”
https://twitter.com/realDonaldTrump/status/1346912780700577792
Bought a dog whistle when I was 10 years old thinking it would be really cool to blow it and have all the neighborhood dogs come running up to me wagging their tails.
But no matter how hard I blew the damn whistle, not a single dog ever appeared. Very sad.
Moral of the story: Dog whistles are bogus.