It probably means that there are two minutes of angle represented by each graduation on the adjustment dial, eg., APPROXIMATELY 2" @ 100 yards, 4" @ 200 yards, 6" at 300, etc. But, it would seem to me that the adjustments on a 3X-9X scope would be finer than that. If I recall correctly, the graduations on my (older) Leupolds are 1 MOA.

Keep yore powder dry!!