N4659 "30.10.4 Terms and definitions [fs.definitions]" (https://timsong-cpp.github.io/cppwp/n4659/fs.definitions ) has no body text or footnotes or subsections. From "30.10 File systems [filesystems]"(https://timsong-cpp.github.io/cppwp/n4659/filesystems#fs.definitions ) it seems that the subsections 30.10.5~30.10.23 should be moved under 30.10.4, i.e. 30.10.4.1~30.10.4.19.