The DuoWiki fandom provides a lot of information on Duolingo, however changes to the application are turning it outdated.
Occasionally you run into some pages that have been written before the introduction of the crowns, with images that are now unfamiliar to most users and conclusions that are no longer valid.
What is worse are the numerous references to Duolingo forum posts. All links have become obsolete since March 22. The DuoWiki badly needs improvement to become the support and reference it once was.