I've just glanced through so don't have detailed comments at the moment. Noted one thing I can comment on quickly: in #24, you cite "zh-Mandarin"; you should change that to "zh-guoyu" (now superseded, but was in fact registered: see http://www.iana.org/assignments/lang-tags/zh-guoyu).
> -----Original Message-----
> From: ISO 639 Joint Advisory Committee [mailto:[log in to unmask]] On
> Behalf Of Rebecca S. Guenther
> Sent: Wednesday, May 07, 2008 11:37 AM
> To: [log in to unmask]
> Subject: new FAQ
> Please see the revised FAQ (which should have been done ages ago). But
> better late than never. Send comments to me if you have any.