See also: bug 25522.
The redirect should work in the same way that http://nb.wikipedia.org redirects to http://no.wikipedia.org.
"bat-smg" was used because Samogitian did not yet have an ISO code. Now it has the code "sgs".
Version: wmf-deployment
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=25522