From the 2021 scene release rules for games (ISO rips) [0]:
> 1.7 The ISO file has to be packed into a RAR archive using the RAR4 or the RAR5 format and the old style volume naming scheme. e.g. grp-gamename.rar, grp-gamename.r00, grp-gamename.r01, ...
> 1.7 The ISO file has to be packed into a RAR archive using the RAR4 or the RAR5 format and the old style volume naming scheme. e.g. grp-gamename.rar, grp-gamename.r00, grp-gamename.r01, ...
0: https://scenerules.org/html/2021_GAMEiSO.html