Every Stage has a pseudo-root Prim which ensures that the namespace hierarchy of a Stage is structured as a tree instead of a forest (i.e. one top-level prim). This simplifies Stage traversal algorithms.
The Prim path for the pseudo-root Prim is
Some applications explicitly show the pseudo-root prim in the Stage hierarchy such as the Prim labeled root in the Tree View in
Other applications, such as Omniverse USD Composer, only imply the root prim. It is left out of the Stage window, but always present via Prim paths or code: