Jim Logajan wrote
Now why the FAA uses one term for the paper it issues and another for
the paper issued by all other nations is beyond my meager ability. It
may be easier to understand quantum mechanics. ;-)

Because the rest of the world dosen't have our Constitution and the
Air Commerce Act of 1926

United State Code TITLE 49 - TRANSPORTATION
Sec. 40103. Sovereignty and use of airspace
(2) A citizen of the United States has a public right of transit
through the navigable airspace.

Bob Moore