As the Presiding Officer of the Senate may not be, and usually is not, aware of the parliamentary situation currently facing the Senate, a parliamentary staff sits second from the left on the Senate dais to advise the Presiding Officer on how to respond to inquiries and motions from Senators (including "the Sergeant at Arms will restore order in the gallery"). The role of the parliamentary staff is advisory, and the Presiding Officer may overrule the advice of the parliamentarian. In practice this is rare, and the most recent example of a Vice President (as President of the Senate) overruling the parliamentarian was Nelson Rockefeller in 1975.