volume naming convention

    The rule for the initial letter holds especially for the geometry volumes:

        C  --  the  general CMS volumes
        B  --  for the beam region
        T  --  for the general tracker volumes
        P  --  for the pixel system
        S  --  for the Silicon tracker and preshower
        G  --  for the MSGC's
        E  --  for the Electromagnetic calorimeter
        H  --  for the Hadron calorimeter and tail-catcher
        M  --  for the muon system
        Q  --  for the quartz fiber calorimeter and low beta quadrupoles

Also ``B'' is devoted to barrel and ``F'' for endcaps. Their place in volume names is not fixed.