Elon Musk and Grimes' Newborn's Name, X Æ A-12, Is Technically Legal but 'Won't Be Accepted'

Two days after Elon Musk and Grimes announced the arrival of their son and shared his unique name — X Æ A-12 — PEOPLE spoke with David Glass, a family law attorney who explains that while the baby boy's name isn't technically illegal, it won't be accepted as valid by the state.

"In California, you can only use the '26 characters' of the English language in your baby name," he explains. "Thus, you can't have numbers, Roman numerals, accents, umlauts or other symbols or emojis. Although an apostrophe, for a name like 'O'Connor,' is acceptable."

Glass says that if the new parents filled out X Æ A-12's birth certificate at the hospital "with the odd numbers, dashes and symbols, it will be submitted and then rejected and they'll be asked to submit it again."

"They have an opportunity to appeal the rejection of the birth certificate application but it's unlikely that it will be granted because, again, California ... has been struggling with using symbols," he adds.

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"They tried to change the [rule] back in 2014 to allow certain characters, accents or umlauts — those sorts of things — and the bill got dropped because [of the cost] to upgrade their computer systems to allow these accents," he tells PEOPLE.

Glass, who also holds a PhD in clinical psychology, clarifies that the rule isn't technically a law but is listed in a handbook issued by the California Department of Public Health's office of vital records.

"Anything that has to be filed with the state, they have a handbook that includes this particular sentence that says the birth certificate must be filled out 'using the 26 alphabetical letters of the English language,' " he says.

"I don't think you can say it's illegal — it just won't be accepted," Glass adds. "So your child won't have an official name and won't have a birth certificate and you can't get a social security number until you have a birth certificate and on down the line."

Grimes (whose birth name is Claire Boucher) confirmed her son's arrival on Tuesday after Musk originally announced the news the previous day, and broke down her son's eccentric moniker — starting with, "X, the unknown variable."

"Æ, my elven spelling of Ai (love &/or Artificial intelligence)," she continued, before sharing that a part of her newborn's name is a nod to the CIA's Lockheed A-12 reconnaissance plane. "A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent." (Musk, 48, later replied to his girlfriend's tweet with "SR-71, but yes.")

Grimes, 32, added that 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. (According to the Chinese zodiac, 2020 is the Year of the Metal Rat.)

The baby is the first for the singer, while Musk, 48, has five sons from a previous marriage. His first son, Nevada, died tragically of SIDS at 10 weeks old in 2002.