The file format of the disc image, used for preservation or emulation.

The version released in Europe and Australia (usually 50Hz/25fps historically, though 60Hz-compatible on HD consoles).

NieR (PS3/Xbox 360) – Multi-Region [PAL/NTSC] ISO Option 2: The Descriptive Archive Style

The version released in North America (NTSC-U) or Japan (NTSC-J).

version (PlayStation 3 or Xbox 360) are you planning to list?

[Release] NieR (Original) - ISO Collection [NTSC & PAL Included] A quick breakdown of what those tags mean: