ATC Watcher ..... thank you for emphasizing the stuff actually important as comparrd to, single instances not too important to begin with.
I'm not getting out any citation to Convention, Annexes or other sources but - I'm pretty sure that the Convention on International Civil Aviation, known to all concerned as the Chicago Convention of 1944, separates State "aircraft" to which the Convention does not apply, from civil "aircraft" to which it does apply. (Whether it's useful to call it "old"....I'm leaving that for some other thread perhaps.)