This article states that Heart Gold and Soul Silver can be used to trade Pokémon both to and from Generation III. I am 99.99999% sure that this is not true. [[User:Sidnoea|Sidnoea]] ([[User talk:Sidnoea|talk]]) 23:44, 30 December 2014 (UTC)
That's my bad. I read the ability on another website but didn't test this myself with my Nintendo DS. You're absolutely right.