With LocatorAutoCreate->True, any Alt+Click that does not hit an existing locator will cause a new locator to be created at the position of the click. Alt+Click on an existing locator deletes the locator.
With LocatorAutoCreate, any Alt+Click that would decrease the number of locators below min or above max will have no effect.
LocatorAutoCreate->All specifies that any mouse click that does not hit an existing locator should create a new locator. Alt+Click deletes a locator.
When a new locator is added, its coordinates are placed at the end of the list of coordinates for the enclosing LocatorPane or other object.