Jet A is the USA version. Jet A-1 is the rest of the world
Possibly. Seems as though if that's true, they have to be interchangable though. A US jet refuels wherever it lands in the world and jets from wherever in the world will refuel with US fuel when they land here. That's the nature of jet travel.
From Wiki:
"The primary difference is the lower freezing point of A-1
-Jet A's is −40 °C (−40 °F)
-Jet A-1's is −47 °C (−53 °F)
The other difference is the mandatory addition of an anti-static additive to Jet A-1.
As with Jet A-1, Jet A can be identified in trucks and storage facilities by the UN number 1863 Hazardous Material placards.[5] Jet A trucks, storage tanks, and plumbing that carry Jet A are marked with a black sticker with "Jet A" in white printed on it, adjacent to another black stripe.
The annual US usage of jet fuel was 20.2 billion US gallons (7.6×1010 L) in 2009"