/usr/ is in libgtkhtml-editor-4.0-dev 4.6.6-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/pkgconfig/
/usr/lib/pkgconfig/gtkhtml-editor-4.0.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libgtkhtml-editor-4.0-dev/
/usr/share/doc/libgtkhtml-editor-4.0-dev/copyright
/usr/include/
/usr/include/libgtkhtml-4.0/
/usr/include/libgtkhtml-4.0/editor/
/usr/include/libgtkhtml-4.0/editor/gtkhtml-editor-common.h
/usr/include/libgtkhtml-4.0/editor/gtkhtml-editor-actions.h
/usr/include/libgtkhtml-4.0/editor/gtkhtml-editor-widgets.h
/usr/include/libgtkhtml-4.0/editor/gtkhtml-spell-checker.h
/usr/include/libgtkhtml-4.0/editor/gtkhtml-spell-language.h
/usr/include/libgtkhtml-4.0/editor/gtkhtml-editor.h
/usr/lib/libgtkhtml-editor-4.0.so
/usr/share/doc/libgtkhtml-editor-4.0-dev/AUTHORS
/usr/share/doc/libgtkhtml-editor-4.0-dev/TODO
/usr/share/doc/libgtkhtml-editor-4.0-dev/NEWS.gz
/usr/share/doc/libgtkhtml-editor-4.0-dev/BUGS
/usr/share/doc/libgtkhtml-editor-4.0-dev/README
/usr/share/doc/libgtkhtml-editor-4.0-dev/changelog.Debian.gz