plain/simple/easy language variant subtag

Hi,

as a web developer, I recently came across a situation where I wanted to
publish a "simple german" translation of a website. The issue is that I
did not know which language tag I should use for it.

In WCAG 2.0, I found the following passage:

    When text requires reading ability more advanced than [...],
    supplemental content, or a version that does not require
    reading ability more advanced than [...], is available.

    - http://www.w3.org/TR/WCAG20/#meaning-supplements

This seemed to require something like I wanted to do. The way I would go
about implementing it would be to add a link tag like this:

    <link href="..." hreflang="de-plain" rel="alternate" />

However, the language tag "de-plain" does not exist.

After reading BCP 47[1] I contacted ietf-languages@iana.org to ask what
they think about adding a generic "plain" variant subtag[2]. I gatherd
from that discussion that it would be easily possible to register
specific, well defined plain language variants. But there is no general
consensus on a generic variant subtag because it is to vague.

In my personal opinion, it would be very useful to have this generic
subtag (imagine using it in Accept-Language headers or having it indexed
by search engines). But I am neither an accessibility expert nor do I
have much expertise with internet standards. So maybe some of you have
some useful insights on this topic or even want to participate in the
discussion at ietf-languages@iana.org yourselves.

So what do you think about this?

Tobias Bengfort


[1]: https://www.ietf.org/rfc/bcp/bcp47.txt
[2]: http://article.gmane.org/gmane.ietf.languages/10778