The software industry is still figuring out the right balance between open and closed, but we at the DataPortability Project believe that communication is the first step. Tell your visitors what they can expect from you and what you expect from them in return. Your Portability Policy explains the ways that your customers can use the digital "stuff" they've entered into your product, including pictures, settings, messages, sounds, lists, or anything else your product manipulates. Can they bring things in? Can they get them out? Can other products use things in-place, or do they need to make copies? Can your product work with stuff that's hosted someplace else?