Since October 2005 there is a ISO 639-2 code for the alemannic
language (~"Swiss German"); [gsw]. See:
Thus, there could be changed [xml:lang="gem-alsatian"] to
[xml:lang="gsw"], and [lang="gem-alsatian"] to [lang="gsw"] in
the html line:
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="gem-
alsatian" lang="gem-alsatian" dir="ltr">
Best regards, Melancholie
(NOTE:) This task was also mentioning that other Alemannic projects should also be renamed, for example https://als.wiktionary.org to https://gsw.wiktionary.org, however and unfortunatelly, those wikis are nowadays deleted (see T169450), so this task would only focus on alswiki renaming.
"als" is also the standard code for "Tosk Albanian", a variant of standard Albanian ("sq"), not distinguished in Wikimedia wiki project names, but that may be distinguished in localisation data (e.g. on Wikidata, or on partner projects like OpenStreetMap, or other opensource applications for various platforms and open data projects). Using "als" instead of "gsw" blocks the specialisation of localized data for Albanian varieties, and breaks the standard BCP47 fallback resolution rules, in projects that would expect a normal fallback to standard Albanian, and certainly not to any varieties of German.