Currently, on Lexemes and Forms, spelling variants can be added with these two formats:
* language code only (fr)
* mis + item about a specific script, dialect, version (mis-x-Q145625)
In the future, this will be improved so we can directly augment a language code with an item:
* for example: cu-x-Q145625
Even more in the future, this rough interface where user has to type the whole code may disappear and be replaced by something more user-friendly, like having an entity suggester.
In the meantime, it would be useful to have links on the "language code" part, and on the extra item part, so people can click on them and see what the item refers to.
So cu-x-Q8209 would be displayed as [[ https://www.wikidata.org/wiki/Q35499 | cu ]]-x-[[ https://www.wikidata.org/wiki/Q8209 | Q8209 ]] .
This may be covered by a gadget or an extra layer of Javascript, not sure.