: This indicates that the file is the second segment of a multi-part RAR archive. You need all parts (part1, part2, etc.) in the same folder to successfully extract the contents. Primary Feature

: Often used in the modding community to denote "Game Guardian" (a memory editor/cheat tool) or a specific release group.

: Likely a project or date code (01/12/22) associated with a Girls' Frontline (GF) asset or patch.