The president-elect’s aircraft was given what is known as a U.S. special call sign earlier this month, according to a review of air traffic control recordings. Using the call sign, as opposed to the aircraft tail number (N757AF) is designed to make it easier for air traffic controllers to provide Trump’s aircraft with special handling.

Trump Force One: Donald Trump’s Airplane

The Federal Aviation Administration and the U.S. Secret Service have instituted special measures to protect Trump’s flights, including placing temporary flight restrictions around his departure and arrival airports. They have also instituted a temporary flight restriction over Trump Tower in New York City through at least Inauguration Day, as well as one over the president-elect’s Mar-a-Lago club in Florida through the holiday season.

Requesters of special call signs generally have broad leeway to request the four- or five-character designator, assuming it hasn’t already been claimed. A Trump spokesperson didn’t immediately respond to a request for comment on the new call sign and whether it was selected as a nod to boxer Mike Tyson, who endorsed Trump for president.

This article originally appeared on TIME.com