DLT or Digital Linear Tape is a magnetic tape data storage technology which guarantees the effective transfer of large files associated with DVD-Video. Replication facilities utilize this highly reliable medium to create a glass master for disc replication. DLT not only offers consistency as an input medium for mastering and replicating DVD titles, it provides the flexibility to include additions to DVD content like CSS encryption, ACP and Macrovision Ripguard. It is also the preferred master format for DVD-9 replication. Because DLT has proved itself, for some time, to be a dependable and flexible media, DVD authors and replicators almost exclusively use this tape format.