Where can I find a list of categories of social media content users post?

I'm planning on creating a general-purpose social media app where people tag their posts with one or more pre-defined content categories. However, I'm not sure as to how a category list should be composed so that content is divided into meaningful sections. I know for example that Pinterest has its own categories, but I don't want to simply copy a list off of another app. My question is, is there a comprehensive list out there made by an open community that I can comfortably use? Second, is there any article/study on categorization I can look at (how it should be done, the impacts of it on user engagement, etc.)? From a UX perspective, I want the list to be well thought-out.