UserItem associates an item with a user and a swap User Item Rating Status this attribute should indicate swap item status available, pending (offer made), swapped (offer accepted) Swap Item this is the item swapped with this user item (an item that was offered for swapping by another user and was swapped with this user item). Swap Item Rating this is the users rating for the item swapped with this user item Swapper Rating this is the users rating for the other user that owns the item swapped with this user item Note: if the user item status is available then theres no values for Swap Item, Swap Item Rating, or Swapper Rating. When the status is pending then Swap Item has a value but not the ratings for the swap item and the swapper. When the status is swapped then the user will be able to rate the swap item and the swapper (the other user) UserProfile A class to manage a List / Collection