A member of the cisco-nsp mailing list asked an interesting question a while ago: he tried to test his EEM applet with the event manager run command and got the “Embedded Event Manager policy not registered with event none Event Detector” message.
An EEM applet (until EEM
3.0) can be triggered only by a single condition. If you want to trigger the applet from the command line (with the "event man run" command), it cannot be triggered by anything else. Such an applet must have "event none" pseudo-trigger.
The event none is used to indicate that "no trigger" is actually what you want to do (as opposed to "I forgot to specify the trigger").