(If anyone knows if the server tells the client what items/materials you have already discovered, please let me know and I'll make it a custom client feature myself)
Anyway, it would be cool to have an Atlas or List of raw materials and items that your character has discovered/learned. This way you would know what you're missing when you try to craft something, or if you can teach something to somebody else.
Oh and make it have a search option too, I suppose.