Zodiac's edit was split in 9 reels. Even though there is no more technical length restriction it still makes sense to divide the movie into logical entities. Final Cut exports an XML file that was used to conform the movie. This conform tool reads the XML, consults the database about the actual frame location of the material and controls the tape robot that loads back that material from the LTO3 drives. With clean data this process needs no intervention. The source frames get cached on the xsan. Conforming a reel again after changes can take only a matter of minutes. The conform tool uses source frames from lto3, disk or vfx frames. Conforms can 'chase' the edit without effort. A new XML simply creates a new sequence of DPX frames.