Last call for ISO 15924-based updates

[Randy Presuhn]

Hi -

> From: "CE Whitehead" <cewcathar at hotmail.com>
> To: <ietf-languages at iana.org>
> Sent: Wednesday, March 18, 2009 8:43 AM
> Subject: Last call for ISO 15924-based updates
...
> Now, I'd like someone to explain to me the benefit of writing something
> like this, in a context such as HTML where BCP 47 language tags can be
> used to tag arbitrary sections of text:
> <span lang="en">
> Send us your re<span lang="en-Zinh">[U+0301]</span>sume<span 
> lang="en-Zinh">[U+0301]</span>.
> </span> 

This would not be a helpful thing to do.  It makes no sense at all.
Folks SHOULD NOT do it.

The only question for this list is whether the uselessness of this
subtag is sufficiently obvious to prevent folks from using it,
or whether we need a comment to explain that this script subtag
will be useless, if not not a potential impediment to interoperability,
since it would break script tag matching.

If folks following this discussion (never mind random developers "out there")
have somehow come to the conclusion that abominations like
<span lang="en-Zinh">[U+0301]</span> would be ok, then in my view
that's a strong argument that the comment really is needed.

...
>  why then is a code like 'zinh' needed at all?

For *our* purposes, it is not needed.  ISO 15924 serves other
purposes, for which having such a code is useful.  It's just
not useful for the purpose of composing language tags.
Before the <span lang="en-Zinh">[U+0301]</span> example
started flying around, I had been convinced that the comment
wasn't necessary.  Now I'm not so sure.

Randy