(NEXSTAR) — In every presidency for over 70 years, the new commander in chief and the first family have gotten Secret Service code names, but did you know they really aren’t all that secret?

Used by presidents since Harry Truman (his was General, though he’d been a captain during World War I), code names were originally meant to be secret since they were used during a time before the encryption of sensitive electronic communications.

With the advent of new technology allowing the president and others to be monitored in many different ways, the names lost their top-secret status. And over the years, the names have become public through government filings, source leaks or simply when agents have been overheard in public.

Now, the primary function of code names is ease of use. They are meant to be quick to say and easy to pronounce and hear.

And it helps to avoid names that may cause undue confusion, as in the case of Vice President Nelson Rockefeller’s wife, Happy, whose code name was Shooting Star. Considering how problematic the word “shooting” could be, it’s not hard to see why she quickly became known as Stardust instead.

Though the assignment of code names used to fall to the Secret Service, now “protectees” can pick their own name from a list maintained by the White House Communications Agency.

Donald Trump said in a 2015 candidate debate that he would choose “Humble” as his code name, but as president, he became Mogul instead.

Once a president has chosen his name, his family gets names starting with the same letter. The Trumps use M, the Obamas used R, and the Clintons chose E.

Some presidents and first ladies had more than one Secret Service moniker. Moreover, if someone doesn’t like their chosen name, it can be changed as long as the new name hasn’t been used before.

George W. Bush, who reportedly once had a drinking problem, was called Tumbler when his dad, George H. W. Bush, was president. It’s no wonder he changed his code name to Trailblazer when he became president himself.

Presidents, vice presidents and their families aren’t the only people who get code names. The Secret Service also uses them for other prominent people such as some top government officials, dignitaries and celebrities.

As a presidential candidate in 2012, former Speaker of the House New Gingrich chose the name T-Rex because of his fondness for dinosaurs. And Pope John Paul II was fittingly called Halo.

However, the names aren’t only reserved for people. They can be given to locations and objects as well. Air Force One, for example, is known as Angel or Cowpuncher, while the presidential state car is Stagecoach.

Castle is the name used for the White House, and the U.S. Capitol is called Punch bowl.

Now that you know some of the “secrets” behind Secret Service code names, what would your code name be?