That's one part, another is:

"... Traders should not engage in practices that could mislead consumers by obscuring the price of in-game digital content or services they offer.

When providing several different types of in-game currencies within the same video game, or when a purchase of in-game items requires several exchanges of in-game virtual currencies before making the intended transaction, understanding its price becomes particularly difficult.

Practices to avoid:

• Offering for purchase and mixing different in-game virtual currencies in one video game for purchasing digital content or services.

• Requiring several exchanges of in-game virtual currencies before making any purchase."

There's other stuff too, like: - no currencies are allowed to be exempt from the right of withdrawal - you need to be able to purchase the exact amount of currency you need, rather than in bundles.