Everyone forgets that in the English games you can ONLY set 10 character long nicknames. For Pokémon, without a Nickname the game displays the species name regardless of length. Hensforth the occassional Pokémon with a name longer than 10 characters. The game does not even read the Nickname field if the nickname flag is turned off.
Thanks to the Global Trading Center shortly after Diamond & Pearl came out, I learned that even though the games do not read the Nickname on same language Pokémon. However, if you say end up with a Pinpul from Japan and Turtwig from France that do not have Nicknames, they will show their proper language knames. Which implies they read from the Nickname field because it a foriegn species. So, as I can confirm when they evolve they take the name that matches the language game they are on. This implies if you trade an 11 character English name Pokémon from a US Pearl to a Japanese Diamond, something in its name WILL change. (Probably just drops the last character.) If anyone can confirm this it would likely help the people making PokeGen better!