This format was played in 2017 North American Internationals and contains the following sets and promos:
- Primal Clash
- Double Crisis
- Roaring Skies
- Ancient Origins
- BREAKthrough
- BREAKpoint
- Generations
- Fates Collide
- Steam Siege
- Evolutions
- Sun & Moon
- Guardians Rising
- XY Trainer Kits: Latias, Latios, Pikachu-Libre, Suicune
- SM Trainer Kits: Lycanroc, Alolan Raichu
- XY Black Star Promos: XY39 - XY211
- SM Black Star Promos: SM01-SM39, SM44, SM50-SM51
Whimsicast has a great article of the format at The Why of PRC-GRI - A Look back at one of my favorite old regulation formats. In it, they go through most important cards, strategies, mechanics and decks. If you want to get into the format, that’s a great resource. Another great place to get to know the format is LimitlessTCG’s NAIC 2017 tournament page where you can find decklists for most of top 64 decks.