Mechanics Question on Catcher OBS

[Ran.D]

Is there a verbal call by PU on catcher obstruction? I think only the DDB signal is required. Since the defense can take either the results of the play, or the obstruction, a verbal call may confuse the defense.

I think BU should ignore the OBS call until after the play is over and call what he sees. If PU doesn't call OBS, but BU clearly sees it, a conference is in order.