This is barely a bug, but should perhaps be fixed anyway:
Open “Settings > Configure Kleopatra… > Appearance > Certificate Categories”, select a certificate category and click on “Set Icon…”. Select “All” in the drop-down menu at the top-left and type alligator in the input field at the top-right.
Result: Kleopatra finds two seemingly identical icons, alligator and org.kde.alligator. Same seems to happen with other icons with names starting with org.kde.
Expected: Kleopatra only has (and finds) either of the two.
Kleopatra ver. Gpg4win-5.1.1.