About Obelisk The Tormentor Official Tournament Card?

Ok so, here's the deal. I recently got this awesome card but reading the effect statement a question popped and I've searched for an answer but no one really knows for sure. The card's effect says: "This card cannot be targeted by effects of Spells, Traps, or Effect Monsters.". Now this is really complicated because it is indeed true that some cards such as Dark Hole, Final Destiny, Raigeki, etc. Are not actually targeting cards, they just destroy all of them, but I've seen other effect cards that have: "This card cannot be destroyed by effects of cards that SPECIFICALLY designate this card as a target". So...what's the deal with that? Obelisk never says SPECIFICALLY. I need an official reference that says how this actually works. Thanks in advance :)