"If you are upgrading to Data Protector 7.00 on Windows, HP-UX, and Linux systems, the enhanced incremental backup database cannot be migrated to the new version. The old enhanced incremental backup repository is deleted from the Data_Protector_home\enhincrdb\mount_point directory. During the first full backup after the client upgrade, a new repository is created at the same location. Notice, that the first backup after the upgrade should be full."
Please help to explain, what the meaning of incremental backup database cannot be migrated to the new version?