Wishing to create Inuktitut language locale json from scratch

[jmp]

Hello, I'm trying to create a new Locale Json from scratch for the Inuktitut language (Canada) (IETF: iu-Cans-CA) but it keeps giving me the "Invalid locale name". I have tried all the possible combinations like "iu", "iu-CA" etc. Is there a reason it won't allow me to create a new language file? I thought the only condition was for the language tag to be part of the IETF list, and Inuktitut is, so I don't know what gives. Help please! Our company is Inuit-owned and operated and it feels wrong not to include their language.

Thanks!