One of the things we struggle with in our use of the forums is that people discuss and ask questions about versions of products. For example, in this forum, there are 2017, 2016-1, 2015-2, etc. versions of InstantForum that someone might have a question or suggestion about. It would be great to allow a tag(s) for a topic that could be used to help people understand where to answer.
It's similar to the "type" above, but certainly some questions might pertain to multiple versions. Over the years we've found tags to be better than categories.
If you add this, maybe have a way to "suggest" tags for people, perhaps off to the side or below this box, to the right of the "notify" and "post" items.