Pokemon Bootleg
There are many ROM hacks of Pokémon, most hacks are distributed by IPS(a file that contains instructions to modify a ROM) patches over the Internet. However, there are some ROM hacks that are sold in game cards. I've seen some of them in China.
Fan Translations
Chinese developers made a lots of fan translations. Fan translations are games in ROM that are translated in a different language. There are not very much official Chinese games, so there are many fan translations. Fan translations are not a type of bootleg, but they are ROM hacks. I played a lots of Chinese Pokémon games, and the Emerald version has a bug: It crashes when you go on the ship and Scott appear. The oldest Pokémon Red/Green/etc. are automatically translated by machine! The texts are nonsense.
Pokémon Jade/Diamond
Keitai Denju Telefang was ROM-hacked and masked as a Pokémon game.
The title changed, the texts changed and even the graphics changed.
Some Chinese developers translated it into Chinese and compiled the game into a game card.