Spells like Mangle(Cat), Faerie fire(feral) (also i heard of other spells with parenthesis  in it's name) isn't usable in TBC in usual way, so we forced to run it as macros or lua. Its not a big deal at all, but when it comes to make fightclasses, you can't use, for example, Mangle.KnownSpell and has to divide druid feral fc in pre-mangle fc and post-mangle fc, which is not very convenient. Droidz, if you can, please fix this issue.

You can enter "Faerie Fire(Feral)()" as the name and it should work. I personally always substitute SpellManager.KnowSpell with an extension function in C#.
 

public static bool IsKnown(this Spell spell)
{
  return Lua.LuaDoString<bool>($"return GetSpellInfo('{spell.Name')");
}