After emerge --depclean I see the following: >>> package: kde-apps/ktnef-15.12.1 * - /usr/lib64/libKF5Tnef.so.4.79.0 * - /usr/lib64/libKF5Tnef.so.5 * used by /usr/lib64/qt5/plugins/messageviewer_bodypartformatter_application_mstnef.so (kde-apps/kdepim-15.12.2)
See also: https://github.com/gentoo/kde/pull/600