to be able to select a category for a blog post. based on the category selected the title of the blog post to show up in a specific color + a flag in order to easily see which blog posts belong to a particular category. also to be able to select to view only blog posts belonging to a selected category
flags and coloring of posts based on category
just like you do in your inbox, you can color your emails based on come rules/criteria, so you can see from one view the category to which a topic belongs to based on its color.
Tags don't really do much (e.g.if you search in a community by a tag used inside the community, it returns no results...)