Catch: The Trappings of Winter/Summer

[Drashna]

Personally, I feel that a +3 is justified. Namely, only +1 for knowledge of the catch.  Don't agree?  Ask a random person how much they know about faeries, the mythological creature, and ask them if they know anything that hurts them or that they just don't like.  I'm willing to bet that they will have heard of faeries but have no idea that iron is the weakness shared by most or all faeries.  It's common knowledge for those who know more than just a little about faeries, but the average person on the street won't.  That, and a lot of faeries can take many forms, including that of humans, if only using Glamor. So it makes it harder to distinguish.

Though, if you and your group decide +4 is appropriate, that's fine. No harm in that. Well, except maybe to the Fae! 

[Tbora]

atleast according to the books the knowledge part applies for people in the know, so the idea is whether or not someone like a low level paranet member might be aware of the weakness which they in all likelyhood would.

[Quazar]

Would Anna Ash have known about iron and the creature of Faerie?  I guess that would depend on what kind of game you're running.  In my game, she would have.  It's not made clear in the books.