Documentation unclear on the pkg parameter

[telenskyt]

The ?document (also build_manual and perhaps others) says about the pkg parameter

pkg - The package to use, can be a file path to the package or a package object. See as.package() for more information.

But what is "file path to the package"? What does "file path" mean? Shouldn't it be "directory" rather than file? Isn't it a path to the package directory, rather than some file? "File" suggests a path to the file in which the package is packed... The documentation of as.package() is not much clearer.

Could you please make the documentation clear and specific? This is quite confusing.