A can be split into multiple parts (volumes) to facilitate easier sharing of large files.
The "Index" file is often a standalone small archive, but it cannot be used to reconstruct the full volumes; it only contains the previews and metadata. Creating PDF indexes, Adobe Acrobat Index And First 10 Volume Previews rar
In a split archive, the first file is typically named .part1.rar (Index 0), the second .part2.rar (Index 1), and so on. A can be split into multiple parts (volumes)
This specific type of "Preview" archive serves several purposes: Adobe Acrobat In a split archive