According to a tweet by Grimes - aka Claire Boucher - the X refers to the "unknown variable", while Æ is "my elven spelling of Ai (love &/or Artificial intelligence)". However A-12 is a reference to the CIA's Lockheed A-12 reconnaissance plane, which is Musk's and her "favorite aircraft" for it possesses, "No weapons, no defenses, just speed. Great in battle, but non-violent".
Grimes later tweeted the meaning of the complicated name, confirming it.
While we're not sure if X Æ A-12 will make it to the top 10 baby names anytime soon, at least he'll nearly always guaranteed to have the most unique name wherever he is! Check it out below.
The couple kept with their non-traditional names, going on to call their second child Saint West, followed by Chicago and Psalm.
While the name "X Æ A-12" is technically legal, a family law attorney recently told PEOPLE that it won't be accepted by the state of California as a valid moniker.
So will we ever really know what's on X Æ A-12 Musk's birth certificate?
Grimes, who is still recovering from surgery after giving birth just three days ago, didn't seem too impressed with musk's public correction, replying: "I am recovering from surgery and barely alive so may my typos b forgiven but, damnit".
That's because in California, where the baby was born, official names can only include the 26 letters of the English alphabet, an apostrophe for names like O'Connor, and a hyphen.