As I wrote at https://bugzilla.mozilla.org/show_bug.cgi?id=1696095#c6 , one option for resolving the parent task, at least for Firefox, is to get ourselves on the disconnect.me list of co-owned domains and to have Firefox respect it when doing first-party state partitioning.
Change requests can be sent to https://github.com/disconnectme/disconnect-tracking-protection/issues and are sometimes acted upon. To file a request, I need a canonical list of registrable domains that we are using. Judging by the existing entity list, they are mostly looking for domains that are actually used rather than parked domains.
Following is the list of files in operations/dns/zones that look like domain names and are not a symlink to parking or ncredir-parking:
mediawiki.org wikibooks.org wikidata.org wikimedia.cloud wikimediacloud.org wikimedia.community wikimediafoundation.org wikimedia.org wikinews.org wikipedia.org wikiquote.org wikisource.org wikiversity.org wikivoyage.org wikiworkshop.org wiktionary.org wmftest.com wmftest.net wmftest.org wmfusercontent.org w.wiki
Can someone please review this list and the method I used? It might not be easy to change it after I file the task.