@Bouzinac added the following in the "Localizing parameter names" section:
It should be possible to use aliases. Eg "date" in enwiki, "data" in itwiki, "Дата" in ruwiki. Either "first" parameter names or aliased names should be working.
I am moving it here for discussion. Perhaps I don't understand the suggestion, but isn't this already what the "Localizing parameter names" idea is about in general? The current proposal is:
These generic parameter names will be the common default names. They will work in wikis in all languages. The localized names will work in the wikis that has that language as its content language.
According to this, "date" will work in English, Italian, and Russian wikis, "data" will work only in Italian, and "Дата" will work only in Russian.
As far as I can see, using a Russian parameter name in Italian or English is probably not so desirable. Using an English parameter in Russian is also not so desirable, but it's just a default fallback. If the parameters are localized in the template definition, then every time a transclusion is transferred from one wiki to another, the service described in the "Automatic parameter translation" section will translate them automatically.
@Bouzinac, does this sound OK, or do you suggest doing something else when you talk about aliases?