With respect to naming, I think the details of the Baker case make it clear that names are not copyrightable. Nevertheless I agree that naming is a creative aspect of API design. It's not a creative aspect of API code though! There it is just an affordance.

The names that we given our APIs are inherent to their behavior and not necessarily the code. Some languages, such as Swift, even mangle API names when they are used so that their names are non-sensical without de-mangling. So why is the name important? It's important for us to understand what the system is doing, but not to the function of the system itself. This might not seem important for us when doing our work, but in the case of copyrightability it's an important fact based on precedent law.

I'm not sure I understand your point about the difference between the API code (where the names are mangled and meaningless) and the API design. Surely the API code is irrelevant here because it is not the part that humans interact with?

In this case the naming is an important factor, as that is the competitive advantage leveraged by Google in copying Oracle's Java API. They were able to tap into a developer resource who was familiar with the style, naming and conventions of Java

The API is the interface between the human and the code, and so copying a familiar interface design can be an advantage when building a platform

> difference between the API code (where the names are mangled and meaningless) and the API design.

API Code = header file or interface files or source code artifacts you need to include in order to make use of the system underlying the API.

API design = a behavioral specification which the system represented by the API implements

> In this case the naming is an important factor, as that is the competitive advantage leveraged by Google in copying Oracle's Java API.

My point is it's an important factor in the design specification, not the code. This makes it an invention. Inventions cannot be copyrighted per Baker; they can however be patented.

> They were able to tap into a developer resource who was familiar with the style, naming and conventions of Java

The Baker case specifically addresses this point by saying embodied practices cannot be copyrighted. Java isn't a book, it's an invention so the proper avenue for protection is a patent and not copyright.

> The API is the interface between the human and the code, and so copying a familiar interface design can be an advantage when building a platform

Again this would be arguable as a patent infringement, but here we are discussing copyright and not patents. What you're describing applies to design patents IMO. [IANAL]

Thank you for the details! I think I understand what you mean now