Huh and what are the unrecognized imput returns, you probly spelled it wrong, the nul message or blank return means the item is not craftable, this is per Sanvean, but I am too lazy to find her post and quote it, Items that you do not have the skill in one way or another to craft and are craftable will give you one of a couple messages telling you so, and in a way, they even tell you why.
Also, by my estimate, less then 30% of items in game currently are craftable, So, by all means, making crafting submissions for existing items, I think Sanvean also made a call for them a while back...hey Sanvean, how is that going?