On tags: on Discourse, tags are really just a different type of category. You can watch, track, or mute them just like a category, and they appear on the navigation bar to the right of categories — like a subcategory.
And although they aren’t displayed this way, you can actually “nest” them — it would be possible to have a “hardware” tag and then if you pick that it follows up with a choice of “CPU” / “GPU” / “RAM” / etc. But I’m not thinking currently that we’ll use that here — seems too complicated.
Anyway, unlike categories, a post can have multiple tags — both “cloud” and “server”, for example.
Tag policy is by category — you can make a category require a tag or not, and you can restrict groups of tags to particular categories. In the plan above, I’m planning for there to be a bunch of tags representing team names in Project Discussions (and require one of those), while there will be more descriptive tags in Announcements.
The feature I’m talking about in the above point is a thing where Discourse will automatically add a tag if there is a keyword match in the text. We have this on Ask Fedora, in an experimental state — see giesen/python-pipenv for more on that.