Difference between Unlimited/Modified

[AzNLeviathan]

Hi, I'm a Yu-Gi-Oh player that just got back into playing PokeMon, and I have a stupid n00b question:
What's the exact difference between Unlimited and Modified?

[PokePop]

First, banned cards in Pokemon. These are banned in all formats:

Ancient Mew
_______'s Pikachu

That's it. And they're not banned for being overly powerful. They're banned for being hard to play or giving one player an unfair advantage over another.

Unlimited: All cards, other than banned, are legal.

Modified: Only cards from recent sets and recent promos are legal. also, old copies of cards that have been reprinted in those recent sets are legal. Currently, cards from Expedition and on are legal, as well as Black Star promos 001 and up. (not 1 and up! Those are the old WotC promos).

[AzNLeviathan]

Unlimited- I heard rumors of how the old/original Sneasel (Beat Up) was banned. Is that true? It does seem pretty broken...
Modified- Sorry, but what packs are from Expedition are up?

[BJJ763]

No Genesis Sneasel was banned from Modified when NEO: Genesis was MF legal.

Expedition, Aquapolis, Skyridge, Ruby & Sapphire, Sandstorm, Dragon, TM vs TA, and the soon coming Hidden Legend.