-devel package header files

So I’m a bit confused about which header files to include in a devel package for a library. The guidelines are a little vague as it just says to include header files, but for example something like libdriveio(included with makemkv) it includes 7 different header files: libdriveio/inc · debian/master · Ben Westover / MakeMKV open source components · GitLab. Would I include all 7 in a libdriveio-devel package? I also don’t know much about headers, do they need to be modified before going into /usr/include? The makefile doesn’t install the headers automatically, so I have to manually install in the spec.

You need to include the header files that a developer will need to compile code that uses the library.

You do not need to include header files that are just needed to compile the library itself that are not required by a user of the library.