The power couple had originally planned to name the newborn “X Æ A-12 Musk,” but were forced to change it to “X AE A-XII” after being notified that special characters and numbers were prohibited. California law dictates that names on birth certificates must employ “the 26 alphabetical letters of the English language,” although apostrophes and dashes are permitted, reports NME.

The cryptic moniker might still look like it was formulated by a cat crawling across a keyboard. However, Grimes, 32, whose real name is Claire Boucher, previously tweeted that the X is the “unknown variable” in algebra while the Æ refers to the “elven spelling of Ai (love &/or Artificial intelligence).” The A-12 at the end was inspired by the Lockheed A-12 reconnaissance aircraft — the couple’s “favorite aircraft” — and Musk’s sole contribution to the name, according to his latest appearance on the “Joe Rogan Experience.”

“The Archangel-12, the precursor to the SR-71, the coolest plane ever,” gushed the 48-year-old SpaceX founder on the podcast.

Despite the long name, Grimes admitted on social media that they simply refer to him as “X,” reports PopCulture.

However, the couple is at odds when it comes to the name’s pronunciation. While Musk told Rogan that letters were pronounced like the letter “X” followed by “ash,” his paramour claimed on Twitter that you follow the X with “A.I.” — that is, the letter A then I.

Either way, both are equally fond of X AE A-XII, who is the singer’s first child and Musk’s seventh. However, despite the abundance of kin, the serial entrepreneur claims that he’s never enjoyed being a father more than now.

“Actually, I think it’s better being older and having a kid,” he says. “I appreciate it more. Babies are awesome.”

A new child isn’t the only reason the tech billionaire is flying high. Musk was recently selected, along with Amazon founder Jeff Bezos, to build lunar landing systems to transport NASA astronauts for the 2024 Artemis moon missions.