Are the call signs of amateur radio operators distinct from call signs in all other radio services, such that there can be no ambiguity even if the relevant license and band(s) of operation is disregarded?
If they are not distinct internationally, are they distinct in the United States?
I'm interested primarily in overlap not the result of an administrative dispute, and between amateurs and a different radio service.
To be accepted, an answer should be complete, even if this means repeating what has already been said. Citations would be nice, too.