It seems that human beings want to tag everything. You can do it with Hyde also. In this example tags are used to represent technologies used to build a particular advanced page. So you can see that the sorting was needed for all advanced topics, but grouping was used only for overview and grouping pages.
Listing by tags
You can also search for combination of tags. If you search for a resource that has sort, tag and group tags, only an overview will be returned.