/usr/share/gtk-doc/html/ is in libxfce4util-dev 4.12.1-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gtk-doc/html/libxfce4util/
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/usr/share/gtk-doc/html/libxfce4util/libxfce4util-Xfce-Generics.html
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