Duolingo Wiki & FAQ (unofficial, but still amazing)
Where can I find a Duolingo FAQ? Check Duolingo's official Help Center (Duolingo Plus/
Purchases, Educators, Ambassadors, Report Bugs, and more!) If you don't find what you're looking for there, check out the these awesome Duolingo Wiki (etc.) guides:
The Wiki's unofficial Duolingo FAQ
What are some common forum mistakes aka faux pas that I can avoid?
How to best utilize the Sentence Discussion forums
How to protect your streak beyond the basics of just equipping a streak freeze.
How to find popular posts without wading through as many sticky posts.
I want to create an XP competition, what should I know?
What does the inside of the Incubator look like? (Wee bit outdated. But, still the same general idea.
All of that ^ and more on the unofficial Duolingo Wiki.
Non-mods pointing out Guideline violations
Community Guidelines Clarification
The wiki too big? Getting lost? Just go to Google and type Duolingo Wikia and a search term such as Clubs, or Streak Freeze and find exactly what you're looking for. Or, use a key word in the Wiki's search bar.
Need a refresher on the Guidelines or Terms of Service? Just click Guidelines or Terms which can be found at the bottom of any definite page. (So, not the forum posts that scrolls endlessly bringing up more posts.)