Although phrased in terms of sharing educational resources and content, the simple rules presented in this post make for a good start for making anything shareable.
I might consider adding something along the lines of “documented”. I have seen plenty of open source software, for example, which meets all the other criteria. Without adequate descriptive and instructional documentation, though, most of the criteria might as well not apply. It’s hard to gauge quality, edit or repurpose something if you can’t make sense of it.