Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
When building a team for gen 4 ubers using arceus, the EV spread suggested by the site is the 252/252/4 spread, even though in gen 4, arceus can only ever have up to 100 EVs in a stat.