Gun 语言使用什么 html lang 值?

What html lang value to use for the Gun language?

对于 Gun 语言的内容,我应该使用什么 <html lang=" "> 值?我在任何官方文件中都看不到它。

Language Subtag Lookup App suggests that the tag for the Gun language is lang="guw". Ethnologue agrees. Wikipedia makes Gun a member of the Fon 方言群。