String sections in an orchestra commonly have their parts marked so that all players switch bows at the same time. This job is usually performed by the principal player in that section. In my former community orchestra, however, the conductor decided to have a professional violinist---who happened to be my private violin teacher---bow the parts instead. I noticed that she wrote her initials, "V.S." at the bottom of one of the pages, which I thought was a little strange; it's hardly a difficult or creative enough task that it justifies a personal signature.
Years later, I've discovered that V.S. in fact did not stand for her name, but is an abbreviation for volti subito, or "turn page quickly".