相关字符串常量的惯用表示法

I am not certain in which way I should represent related string constants, namely language codes, in Go.

1. The only occurrence in the standard library, of which I am aware, uses untyped string constants and prefixes the variable names with the "type".

   const LanguageEnglish = "en"
   

2. There is the possibility to declare an extra type.

   type Language string 
   
   const English Language = "en"
   // or
   const LanguageEnglish Language = "en"
   

   But any arbitrary string can be converted to the type anyways, so I can not remark any advantage.

   Language("en")
   

Essentially two questions arose from the prior observations:

1. Should the string constants’ names be prefixed by their "type"?

2. What are the benefits of using a custom type in contrast to untyped string constants?