This feature is now available via:
https://github.com/discourse/discourse/pull/5730/files
Note that the “minimum tag validation” on a category will not happen if:
- tagging is disabled globally
- acting user is staff
- acting user does not have sufficient trust level to use/add tags
The option to enforce tagging is available per category. If the tagging is enabled, the setting Minimum number of tags required in a topic
will appear under “Edit Category” modal => “Settings” tab. The setting value defaults to 0
.