Removing Klipper from one's KDE session is a legitimate need, e.g. for security reasons as discussed here (1), or in order to use another clipboard manager instead.

Currently, nowhere in KDE's system settings, Klipper's documentation, nor Klipper menus, a clear way of doing so is provided.

As indicated in (2), removing Klipper can be achieved by unchecking "Clipboard" in "System Tray settings > Additional Entries" ; but by doing this the user is let unsure whether
- Klipper does not appear in the systray, *but* is still running in the background ;
- Klipper won't be running after restarted the session ;
- Klipper is no longer running at all

This is clearly a usability issue, which has been bothering people since at least 2003 (3).

(1) https://forum.kde.org/viewtopic.php?f=66&t=128086
(2) https://bugs.kde.org/show_bug.cgi?id=352171#c15
(3) https://groups.google.com/forum/#!topic/alt.os.linux.suse/GFsc2xZHeuA