# Rule-based virtual category
**URL:** https://meta.discourse.org/t/rule-based-virtual-category/374247
**Category:** Feature
**Tags:** tags, tag-groups
**Created:** [July 15, 2025, 6:02am UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247 "2025-07-15T06:02:47Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@volanar](https://meta.discourse.org/u/volanar)
#### Post date: [July 15, 2025, 6:02am UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/1 "2025-07-15T06:02:47Z")
This revolutionary feature can solve the problem of a single topic being assigned to multiple categories.
This also partially solves the problem of low category nesting to create a convenient community structure.
This feature is used in e-commerce to create summary categories based on rules (such as product attributes). This allows you to have one product in multiple categories.
In discourse, a virtual category can be created (or added to an existing one) based on tags or a group of tags.
It is necessary to make a new setting in the category settings.
When you select the “virtual category” checkbox, a window opens with a selection of tags or a group of tags, based on which topics with such a tag are automatically added to this category.
For example, we have a category about cats. We want to put one breed of cats in a separate category, but we want to leave the topics in the old category. We create a new category and based on the tag, for example, Maine Coon, the category will automatically be filled with topics with the Maine Coon tag, there can be a large number of them. This is one example of use, in reality there are many more.
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### Author:  [@Jagster](https://meta.discourse.org/u/Jagster)
#### Post date: [July 15, 2025, 6:32am UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/2 "2025-07-15T06:32:41Z")
As I see this you want to show same listing for a tag, what a tag already gives.
What rules should those tag based topics follow in that virtual category, from original or would a virtual category has its own? And if original, what would happen when topics using same tag come from different categories with different rules?
Otherwise… Discourse is a wonderful tool for discussions, and e-commerce apps and platforms are the best option for selling things.
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### Author:  [@volanar](https://meta.discourse.org/u/volanar)
#### Post date: [July 19, 2025, 7:26am UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/3 "2025-07-19T07:26:02Z")
> [@Jagster](#):
>
> As I see this you want to show same listing for a tag, what a tag already gives.
How often do you navigate by tags? I never
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### Author:  [@Jagster](https://meta.discourse.org/u/Jagster)
#### Post date: [July 19, 2025, 7:36am UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/4 "2025-07-19T07:36:56Z")
Almost all the time.
However, it requires that tags are used correctly on the forum. The most common reasons for not using tags are:
- the user does not understand how tags work
- tags are not made for users, but for the administration
There is the third reason too: a user never search something where categories or tags are useful.
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### Author:  [@RGJ](https://meta.discourse.org/u/RGJ)
#### Post date: [July 19, 2025, 12:50pm UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/5 "2025-07-19T12:50:50Z")
And what would be the advantage over tags exactly ?
Thought experiment: rename “tag” to “virtual category”. What would you still be missing?
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### Author:  [@volanar](https://meta.discourse.org/u/volanar)
#### Post date: [July 24, 2025, 9:01pm UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/6 "2025-07-24T21:01:03Z")
You misunderstood me. This is not a replacement for tags, this is the only way to use one topic in several categories. If a topic equally belongs to several categories, then now it is impossible to do this, you can only select one category. Thus, you can create a new category based on the rules, using 2-10, etc. tags. Or add rules to the old category. Once again, tags are used as rules for linking topics to a category. Half of my topics need to be linked to several categories, but I can only link a topic to one category
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### Author:  [@Jagster](https://meta.discourse.org/u/Jagster)
#### Post date: [July 24, 2025, 9:37pm UTC](https://meta.discourse.org/t/rule-based-virtual-category/374247/7 "2025-07-24T21:37:22Z")
> [@volanar](#):
>
> Once again, tags are used as rules for linking topics to a category.
Except that isn’t how tags are used. Both are taxonomies. Categories are hierarchical and work vertically. Tags are (mostly) non-hierarchical and act horizontally.