Multi-billionaire tech mogul Elon Musk and his girlfriend Grimes have officially named their baby X AE A-XII Musk. The birth certificate shows clearly the baby boy's first name as X, middle name X AE A-XII, and surname Musk.

This name, according to the certificate, has been registered in the state of California, reports Business Insider. Shortly after the birth, the couple had announced they had named their son X AE A-12. However, the couple discovered they would have to change the name as per the Californian law, names written on birth certificates must be written using only the 26 alphabetical letters of the English language.

Musk and Grimes Officially Name Their Baby

Elon Musk
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Grimes confirmed the name, and explained the meaning in another tweet: "X is the 'the unknown variable', AE is her 'elven spelling of Ai", A-12 is the "precursor to SR-17". "X, the unknown variable. AE, my elven spelling of AI (love &/or Artificial intelligence), A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent + (A=Archangel, my favorite song)," she posted.

The Tesla and SpaceX CEO has six children with ex-wife Justine Wilson and this one is the first child with his new girlfriend. Grimes also revealed she does not want to 'gender' her baby, saying they can "decide their fate and identity' on their own accord.