Brendan,
In the United States you can trademark a projection and Buckminster Fuller is the one example of this that comes readily to mind. The Dymaxion map projection is trademarked and you must contact the Institute to use it. You can read that here: https://www.bfi.org/about-fuller/big-ideas/dymaxion-world/dymaxion-map .
Stanford holds the Fuller archives. We spoke to the folks at the Buckminister Fuller Institute about putting the projection into the public domain to encourage wider usage, but were not able to convince them of the worth of this move.
Best,
Julie
****
Julie Sweetkind-Singer
Assistant Director of Geospatial and Cartographic Services
Head, Branner Earth Sciences Map Library & Map Collections
397 Panama Mall, 2nd floor
Stanford University
Stanford, CA 94305
650-725-1102
George,
I don't think you can copyright a projection. Copyright is protection for an artistic/literary expression. A particular map can be copyrighted for the style in which it is drawn (linework, color scheme, fonts), but not the content of it (unless a map of a fictitious area) or the projection. The mathematics of a particular projection would possibly be patentable, but not copyrightable.