According to the FAQ, it protects against...
* all Enchantment (Charm) effects
* any Enchantment (Compulsion) effects, which allow ongoing control
The latter is pretty much only Dominate (definitely not Command or Suggestion). Ongoing control means, that you can not only give 'orders' once (which Suggestion would basically allow), but rather give new 'orders' throughout the duration. Only Dominate really does so (from the Core Rules, anyways).
Bye
Thanee