Items that were not donated, or sold, can be transferred to a maximum of 1 additional event. This gives them another chance to sell, however, if it didn't sell the first time, there's a reason. Please consider lower your price, and improving how the tag is displayed.
You can transfer unsold, not donated items from the Unsold Items page. Check the items you wish to transfer, then click Transfer Items, and they will be moved to your Current Items.