None? The Supreme Court and the Federal Appeals Court moved the situation from APIs not being copyrightable to their copyrightable but not being usable in the

None? The Supreme Court and the Federal Appeals Court moved the situation from APIs not being copyrightable to their copyrightable but not being usable in the monopoly-enforcement fashion that the copyright-holders generally intend. So there! This kind of silliness isn't without precedent. Font shapes and expressions can't be copyrighted but font names can be. And that's worth something to the font creator.