Backup splitting and simplified file naming
When a backup is split according to backup splitting settings, the same indexing is used to also name parts of the backup. The file name for the next backup will have the next available index.
For example, suppose that the first backup of the archive MyData has been split in two parts. Then, the file names for this backup are MyData1.tib and MyData2.tib. The second backup (supposing that it is not split) will be named MyData3.tib.