Elon Musk and Grimes tweaked their son's name in order to comply with state law. The singer revealed to her social media followers that she had to make some minor changes to her baby's name. Instead of "X Æ A-12" she removed the number 12 and changed it to the Roman numerals Xii. Now the baby's name is "X Æ A-Xii."

"Roman numerals. Looks better tbh ... one dash is allowed," Grimes wrote on Instagram in response to a fan who asked about the name change.

"Did you change the baby name because of Californian laws? What is the baby's new name?" the fan asked.

"Nice! Just removed the numbers to conform to California law," a fan reacted to the name change.

Musk and Grimes welcomed their first born on May 4 and announced his name on Twitter, much to the confusion of readers who struggled with its pronunciation. The name also caught the attention of the state of California because of the number "12" in the name.

Matt Conens of the Office of Public Affairs of the California Department of Public Health, confirmed in an email sent to USA Today that the name "X Æ A-12" is not allowed under California state law.

"Vital records must be completed with the 26 alphabetical characters of the English language and appropriate punctuation such as hyphens, apostrophes, periods, and commas," Conens wrote.

The musician and the CEO of Tesla came up with the name together, although Musk said he only contributed "A-12." The SpaceX founder told Joe Rogan how to pronounce his son's name and said X just stands for the letter X and Æ is pronounced "Ash."

Grimes, on the other hand, had a different explanation. She said "X" is an unknown variable while "Æ" stands for her elven spelling of Ai (love &/or Artificial Intelligence) and "A-12" as the precursor to SR-17 (her and Musk's favourite aircraft).

Musk explained their son's name a bit further in a couple of tweets. He corrected Grimes on the aircraft name from SR-17 to SR-71 and that A-12 stands for Archangel-12.

SR-71, but yes

— Elon Musk (@elonmusk) May 6, 2020

Archangel-12 pic.twitter.com/s9g69SU1Ju

— Elon Musk (@elonmusk) May 6, 2020
Elon Musk flamethrower
Elon Musk and Grimes change their son's name to X Æ A-Xii. REUTERS/Rebecca Cook