In the Search Manager page when trying to create a new Filter, the drop down for filter property doesn't contains category as type. Not even cm:categories of something related.
TAG is selectable as a property and tags are a category type, so it doesn't make sense why the property tag is selectable and category isn't.
Customer need to be able to configure a filter based on categories (cm:categories) in search manager as the same way it works with tags.
Business Use Case
Customer want to enforce that categories are set on documents in the repository. Customer then want to be able to filter the search results for their query based on the categories of the documents returned, the way it actually works for tags.
it is really crucial to business decision on whether customer should use categories at all if this feature is missing.