https://go.googlesource.com/exp/+/3e424a577f31e85f7a95c18c87066fee88139baa/utf8string/
utf8string - exp - Git at Google
expgitgoogle
https://learn.microsoft.com/en-us/windows/win32/seccertenroll/about-utf8string
UTF8String - Win32 apps | Microsoft Learn
The ASN.1 UTF8String data type is encoded into a TLV triplet that begins with a Tag byte of 0x0C.
appsmicrosoftlearn