Alright, so DP1 is Diamond & Pearl, DP2 is Mystery of the Lakes, and DP3 is Shining Darkness. Why does one of Pokemon-Card.com's articles mention DP5?
EDIT: I ran the paragraph through a translator (which are completely unreliable, I know), and from what it says I'm assuming it's talking about having all 493 Pokemon represented by at least one cards in sets DP1, DP2, DP3, DP4 and DP5.
('e' with an accent isn't working for me for some reason.)