Mirrored topic: same topic in two categories

Sorry if I am redundant, but I have not found any similar topic …

Recently, Workflowy, my second favorite web platform (Discourse is the first!) has implemented mirrors, which allow to have an element in more than one location. Like a pointer*.

Sometimes, you know, you have a topic that should be in two categories simultaneously. Yes, I know perfectly well the potential of tags (and Workflowy too), but I’m not talking about that.

Is there something similar to mirrors in Discourse? Is its implementation planned? If the answer is “No” to the two previous questions, what do you think of the idea?

I have seen a few questions asking for this type of functionality. Can you give an example of where it would be useful to have a Discourse topic appear in two categories?

Hi Simon,

One example:

  1. I have three main categories: Elementary, Middle and High School. They are quite independent categories (90% of the topics do not interest the others). There are more common categories, but I would not like to add a lot of categories (10-15 max).

  2. I would like to share a one topic about Educational robotics to everyone.
    2.1. I can create a category called “Educational Robotics”, I know, but it generates some dispersion in some not competent users. Some users will create new topics talking about robots in “Elementary” category (because they are an elementary teacher) and some users will create in “Educational robotics”.
    2.2. I can triplicate a topic, true, but I would like that all community talk about together from his “natural place”.

It is a classic problem in hierarchical systems. Tags can help, but require supervision and maintenance when users are not digitally competent. Automatic tags based in content (great new feature!) can help also, but mirrored topics can be useful in some scenarios, I think.

Thanks, Simon, for your attention.


Why not use tags? Then you can tag the same topic with two different tags.

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Hi Jeff,

Honestly, I don’t have a lot of experience, but I sense that some communities work better when the content is very specific. If I am an Elementary School teacher, I don’t want to read content about college entrance exams. And vice versa.

But they are not totally independent communities either because there are some topics that may be of interest to all of them (although not too many). I come back to my example to answer your question. I have 3 big categories “Elementary school”, “Middle School” and “High School” and I want to post a topic on “Scratch, a fun and easy programming language”.

I can create the topic and tag it as “Elementary School” and “Middle School” but where do I put it?

  • If I create a “General” category, I will soon have a mixed bag, where some users will publish things that would be better in other categories. I’m not a big fan of “General” or “Miscellaneous” categories.
  • If I create a more specific category such as “Programming languages” or “Coding”, many users will not subscribe because they are not too interested in the world of programming, although they might be interested in Scratch if you present it in its natural category (ex Elementary School)

I know that it is possible to create sidebars (using discourse-category-sidebars) and put tag links in them. It would be a solution, but it would imply that the users correctly tagged each of the posts. And it would have two entry points: the category (Elementary School) and the tag (Elementary School) with different contents …

I hope I have explained myself well. Thanks for your attention, Jeff, it’s an honor. And I will not miss an opportunity to tell you how great your platform is.


Hey @jmeler :wave:

If I’m following correctly, I think one answer could be a partially restricted “General” category. You can set the category restrictions such that all users can see and reply, but only staff (or a designated group of your choosing) can create new topics. This should avoid any opportunity for categorization chaos. Take a look at How to use category security settings to create private categories for more information.

Another optional tool if you expect a lot the generalized content to be user-submitted is to set the “General” category up so that all new topics must be approved by staff. This way you would have a filtering system.

You may also want to investigate the usefulness of Discourse-docs: Documentation Management Plugin. You would need to teach your users of its existence, but it could be a good way to organize everything.

I don’t expect mirrored topics to be on the roadmap any time soon, so I’m hopeful one of the above solutions will end up being a workable alternative! Let me know if you have questions.


It sounds interesting, and I understand that the mirrored topic is a big paradigm change. Thank you Taylor! I will investigate it soon.

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