The Latched and Toggle Enable events are Meta Events. They are named like this because they are events used to control the state of the application.
Depending of the input value, these events will enable or disable the input for the messages set as targets.
For example, you can imagine that you want to deactivate only the acceleration sensors of the Wiimote with the press of a button. The button would be configured with a Latched Enable or Toggle Enable event with an acceleration parameter (e.g. pitch) as a value.
If the button has a 'latched' enable event, then pressing the button will invert the state of the target, and releasing the button will revert the action back to its previous state.
If the button has a 'toggled' enable event, then pressing the button will invert the state of the target, but it will take a release and another press to revert it to its previous state.