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