ISS had a huge hacking scene in Latin America back in the '90s, I guess that's what the topic creator is talking about. From Campeonato Brasileiro '96 (ISS), Campeonato Argentino (ISS) to Campeonato Brasileiro '98 (ISS Deluxe), we had a lot of those hacks back in the day, so much that some people didn't even know the original games. If you try to download the original ROMs from a fullset, you'll probably get all those hacks in the same pack.
Also, hacking for Pro Evolution Soccer/Winning Eleven was so extensive back in the PS1/PS2 days that there are still releases nowadays, where they've swapped the whole narration with a Portuguese/Spanish narration, made every national league and so on. They have a pretty good set of tools for this too.
Another modding scene that's still very active is for Dragon Ball Budokai Tenkaichi 3 (PS2). They just released the Dragon Ball Super characters.