So labelling a pump as "above-ground" or "in-ground" is really nonsense.
Sorry but I have to disagree with this. There are some fundamental differences between a AG pump and an IG pump. Most AG pumps are NOT self priming so would not work on an IG pool at all. Also, the rating of AG pumps tends to be much higher than the equivalent IG pump. For example, a 2 HP Optiflo (AG) has about the same flow rate as a 1/2 HP Northstar (IG) so you need to be really careful about using an IG pump on a AG pool because it could very easily exceed the maximum flow rate of the filter.