Elon Musk & Grimes Slightly Change Son's Name on Birth Certificate as Singer Reveals Nickname for Baby
Though the Tesla CEO, 48, and the singer, 32, initially named their baby boy X Æ A-12, a birth certificate obtained by The Blast showed that the two had changed the unconventional moniker to X AE A-Xii.
In the document, the child's first name is listed as X, while his original middle name — which featured the "Æ" symbol and the number "12" — has been altered to AE A-Xii.
It's unclear exactly why the parents changed the name, though family law attorney David Glass recently told PEOPLE that California only accepts the use of the 26 characters in the English language for baby names as the state "has been struggling with using symbols."
"Thus, you can't have numbers, Roman numerals, accents, umlauts or other symbols or emojis," he said. "Although an apostrophe, for a name like 'O'Connor,' is acceptable."
Grimes — whose birth name is Claire Boucher — first confirmed that she altered her child's name on Sunday. When a fan on Instagram asked if she had changed the unique moniker, she wrote back, "X Æ A-Xii."
After another follower commented, "Nice! Just removed the numbers to confirm to California law," Grimes responded, "Roman numerals. Looks better tbh."
At the time, Grimes also told followers that "one dash is allowed" for the name.
While X AE A-Xii's name is certainly still an unconventional one, Grimes recently told Bloomberg that she refers to her baby boy as "Little X" for short.
The new mom previously gave fans some insight into what their son’s unique name meant, explaining on Twitter that X represents “the unknown variable” and "Æ, my elven spelling of Ai (love &/or Artificial intelligence).”
She went on to share that part of the name is a nod to the CIA's Lockheed A-12 reconnaissance plane, which has “no weapons, no defenses, just speed. Great in battle, but non-violent.” The "A" in the name also represents "Archangel" — which she said is her "favorite song" — while the number "12" stood for the Chinese zodiac sign of the rat.
She also broke down the pronunciation of the name, telling one Instagram user earlier this month: “It’s just X, like the letter X. Then A.I."
RELATED VIDEO: Elon Musk Explains How to Pronounce Son X Æ A-12's Name, Says Grimes 'Mostly Came Up' with the Idea
However, Musk offered up a different pronunciation during a recent episode of The Joe Rogan Experience podcast. While he revealed that Grimes was actually the one who "mostly came up with the name," Musk said that X is spoken "like the letter" while "the 'Æ' is pronounced like 'ash.' "
During the show, Musk also proudly proclaimed that the A-12 part of his son's name was his idea, saying that he wanted to pay homage to the Lockheed A-12.
"A-12 was my contribution," he said. "The Archangel-12, the precursor to the SR-71, the coolest plane ever."
The baby is the first for the singer, while Musk has five sons from a previous marriage. His first son, Nevada, died tragically of SIDS at 10 weeks old in 2002.