Hmm. Under the International 8-Ball Rules, which are used in Ultimate Pool, it's the tip that matters, not the ferrule. "Positioning the cue ball with the cue is allowed as long as the tip of the cue is not used."... The ref told me that he did not see Justin touch the ball with his ferrule so he did not call a foul. ...
Under WPA world-standardized rules even the tip can be used in positioning the cue ball, "but not with a forward stroke motion."