Pinyin: the prefix

[Phillips, Addison]

> 
> "Both" certainly makes no sense.  The first Prefix: line says:
> "Tags that
> have 'pinyin' SHOULD also have both 'zh' and 'Latn'."  The second
> Prefix:
> line says: "Tags that have 'pinyin' SHOULD also have 'zh'."  So the
> first recommendation subsumes the second.

Not exactly. The actual relationship is MAY. The Prefix specifically indicates "(a language range) whose subtags are appropriate to use with this subtag" (Section 3.1)

MAY is a much weaker recommendation than SHOULD, in RFC 2119 keywordese.

> 
>  But in any case, tag
> creators are free to use 'zh-wadegile' if they want to.

That is true.

In any case, I now support having just the "zh-Latn" prefix. 

Addison