Hey everyone!
As you probably know, the Wikimedia cluster includes not just "normal" wikis like English Wikipedia and Albanian Wiktionary, but odd ones like the Wikimedia Belgium chapter website https://be.wikimedia.org, Test Wikidata https://test.wikidata.org/wiki/Wikidata:Main_Page, and the English Wikipedia Working Group on Ethnic and Cultural Edit Wars wiki https://wg-en.wikipedia.org/wiki/Main_Page.
As far as I know, however, there's no standard definition of "normal" wiki to use when doing analysis.
So I've started meta:Research:Wiki https://meta.wikimedia.org/wiki/Research:Wiki with draft definitions of "public wikis" and "content wikis", along with some initial documentation about wiki metadata (names, project groups, etc.) which I plan to continue to work on.
I encourage you to edit or comment on the talk page!