I wrote:
bsd is not an ISO 639-2 language code. Subdomains may
be either:
* An ISO 639-1 language code (e.g. en)
* An ISO 639-2 language code (e.g. als)
* An RFC 3066 language code (e.g. zh-min-nan)
* A descriptive name longer than 3 letters (e.g. tokipona)
Do you have a second preference?
It doesn't seem to be in SIL or LinguistList, they both lump it in with
Allemanisch. So I don't think you can construct an RFC 3066 code for it.
So that just leaves
baseldytsch.wikipedia.org .
-- Tim Starling