Elon Musk and Grimes welcomed their baby boy on Monday night, and shared photos confirming both Grimes and the baby were doing well. But the Tesla and SpaceX CEO has already caused confusion over the baby’s name, which he tweeted was “X Æ A-12 Musk.” While it’s not clear whether it’s been made legal, Grimes broke down each section of the name in a tweet last night. ‘X’ refers to “the unknown variable,” according to the singer. ‘Æ’ is “my eleven spelling of Ai (love &/or Artificial intelligence).” Finally, ‘A-12’ is a nod to the “precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent.” The ‘A’ in the ‘A-12’ is short for Archangel, which she says is her favorite song. However, it isn’t immediately clear which song titled ‘Archangel’ she’s referring to. How to pronounce the name is anyone’s guess, though some have pointed out that Æ can be pronounced like ‘ash.’

Page Six has the pictures!