/usr/share/kf5/kdoctools/customization/fo/ is in kdoctools5 5.18.0-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/kf5/kdoctools/customization/fo/catalog.xml
/usr/share/kf5/kdoctools/customization/fo/contributor.entities
/usr/share/kf5/kdoctools/customization/fo/entities/
/usr/share/kf5/kdoctools/customization/fo/entities/fdl-notice.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/gpl-notice.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/help-menu.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/install-compile.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/install-intro.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/lgpl-notice.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/report-bugs.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/underArtisticLicense.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/underBSDLicense.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/underFDL.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/underGPL.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/underX11License.docbook
/usr/share/kf5/kdoctools/customization/fo/entities/update-doc.docbook
/usr/share/kf5/kdoctools/customization/fo/lang.entities
/usr/share/kf5/kdoctools/customization/fo/strings.entities
/usr/share/kf5/kdoctools/customization/fo/user.entities