If I ban an item and set its meta (damage) value it does block the correct item, but it also blocks all other values of that item as well. The item wont get locked and turn into the locked version of the item, it just wont let you place/use it and it still displays the notice of it being banned in chat.
This is my blacklist file:
http://pastebin.com/a4CykeHd
Image of example item:
http://imgur.com/kBiGLBo
Both have the same item name but different meta value, I only have one actually blocked in my blacklist file though.