Per the spec [1]:
user/ – end-user content such as concept guides, advice, tutorials,
step-by-step instructions for using the CLI to perform specific tasks,
etc.
The remaining content all ends up in here.
[1] specs.openstack.org/openstack/docs-specs/specs/pike/os-manuals-migration
Change-Id: I480eee9cd7568efe2f76dd185004774588eb4a99