Hi Artilex -- one thing I've noticed is that you are putting categories on pages that don't really fit with the category. For example, Dutch (Netherlands) for English is a page describing a course on Duolingo. English and Dutch (Netherlands) are pages that describe languages. These are two different things, and so we have different categories for them. Dutch (Netherlands) for English gets a "Courses" category on it (in this case, Category:Phase 3) and English gets the Languages category. That way, if a user wants to see all the Course pages we have, they go to the Course categories. If a user wants to see all the language pages we have, they go to the Language categories. That's why I've remoevd the Languages category from some of Course pages that you've added it to. I hope this makes sense!
One more note on categories -- if a particular article is in a category, it's not necessary to put it in the parent category as well. For example, if a page is in the "Spanish" category, it's not necessary to put it in the "Languages" category, since "Spanish" is already part of the "Languages" category. By limiting the number of categories to only the ones that are needed, we make them easier to use and less cluttered. Thus, English for French doesn't need to be in Category:Courses, since it is already in Category:Phase 3, and Category:Phase 3 is a subcategory of Category:Courses. Hope this makes sense!
I've noticed you adding a lot of content to the skill pages. However, although sets of words cannot be copyrighted, Tips and notes most certainly are. So whenever these are added please make sure you reference the source properly or else we may end up having to remove them all.
This problem is in a lot of skill pages for many languages.
Actually since the content is being copied verbatim and in full it's not enough just to cite the source, the rights owner also has to approve of the content being here, which includes allowing the content to be available under the CC-BY-SA license.
Alternatively, since the content is already on the Duolingo website, we may not really need to copy it here anyway. The only use I can see for it is for people using the mobile apps who don't have access to tips and notes, but Duolingo seems to be working on a mobile-friendly website that includes tips and notes, so they could use that instead when it's available to them.
This is a good point. But it would involve either deleting all those tips and notes, or getting overall permission to add them here. That is a problem considering that we will have no way of proving that the owners actually approved their content being here. Emails can be forged, and a post in a forum is not really official proof of anything.
So I guess the best solution is to remove them all.
As long as you're the user who created them, or the tips have been released under CC-BY-SA or in the public domain and you add a notice attributing them accordingly, then they're fine. See community:Help:Copyright for more info.
Artilex wrote: True, I guess I should delete them. What about user-created tips?
You can reference/add short user tips, provided you attribute and reference them properly.
As far as tips and notes are concerned we already have a nice repository where we can fetch this data, e.g. [], []. The benefit is that all those pages are already CC-By-Sa, and are more in-depth in some cases.
The down-side is that these pages may not be as detailed (or exist at all) in some more obscure languages.