It's something different but related. It "allows the group administrator to create and manage different custom sections of the site. Custom sections serve like url directories. so if group administrator of group travel at photo.net defines custom section sweden (e.g. photo.net/travel/sweden), he will be able to upload files for this section (see content_files table) in order to display the file photo.net/groups/travel/sweeden/stockholm.html"
You can check out the documentation at /doc/custom-sections.html if you'd like. Again, I couldn't figure out how to add a custom section for a group under ACS classic.
