I really don't like the way we consider so many moves to be variations: move variations. I have no problem with Elemental Fangs, Elemental Punches, OHKO moves, Pledge moves, Blue Flare/Bolt Strike, Counter/Mirror Coat, etc.; and Dig/Dive, Eruption/Water Spout, etc. don't really bother me. However, when the PP or targeting is different, or the effect is different other than by something like the status ailment it inflicts or the stat it reduces, they should not be considered variations.
Some ridiculous examples currently considered to be variations include Fire Blast/Seed Flare (10% chance of burn/40% chance of lowering Special Defense), Needle Arm/Force Palm (15PP 30% chance of flinch/10PP 30% chance of paralysis), Fling/Natural Gift (15PP flings item to damage foe/10PP consumes Berry to damage foe).
Ability variations aren't perfect either; really, Storm Drain is not a variation of Sap Sipper just because it makes you immune to a certain type - it is a variation of Lightningrod only, while Sap Sipper is a variation of Motor Drive. Also, I'd rather not call Dry Skin a variation of Rain Dish and Ice Body due to its other effect.