[PlunderBunny]

The original iPhone was 2G, but it was just called 'iPhone' I think. The iPhone 3G and iPhone 3GS models came after.

[gattilorenz]

I remember buying an iPhone 2G when the 3G was already out, and I still have it.

2G isn’t written on the case, but everybody referred to it as “2G” to differentiate it from the newer model.

[netsharc]

It's like World War I, it wasn't World War I until II showed up.

[DonHopkins]

And in space, the Space Gray iPhone was just called the Gray iPhone.