This is an extremely helpful paper for those creating works that lie between sculptural and functional works and copyright does not cover functional objects but can in some cases cover aesthetic aspects of the functional objects. What we like to call, 'the grey area'. With this distinction the paper also clarifies a really important point which has been confusing for many people, a Creative Commons license cannot be used to legally protect a functional object. We have seen many people share their functional 3D files with a Creative Commons license in a number of places online, although this is not legally binding, it does offer a social construct that should be respected, a way to communicate the way in which you would like to share, and a possible framework for the future.
Take the time to read the paper, it is an incredibly useful resource for all of us navigating through unchartered waters.
The paper is shared under a Creative Commons license, of course... Great work by Michael Weinberg and his team.