Here’s a plain-text breakdown of what that string typically means in the context of Nintendo DS ROMs:
The game brought the "Physical/Special split" to the Johto region, meaning moves were finally categorized by their nature rather than their type. This made Pokémon like Sneasel or Gyarados much more powerful and fun to use compared to the original GameBoy versions. 4. The Pokéwalker
: (U) denotes the North American (USA) version.
