Matthias Pfefferle@michael_martinez why would you like to have tags that are only for the fediverse but not shown in the blog. Even Mastodon creates archives for tags.
To have a properly working solution, that is compatible with Mastodon, we would have to introduce a different kind of taxonomy which also creates archives, but different ones.
On the other hand there are requests to have the tags even more dominant and create Actors for them, so that if is possible to follow tags and categories.
All GNU social JP content and data are available under the