I don't know if there is a code. But you can complete de Dex by seeing all Pokemon in platinum. All Sinnoh-dex Pokemon can be found ingame.?
pelipper is the 120th Pokemon in the platinum sinnoh dex.
see all the Pokemon in the sinnoh dex
no he isn't in sinnoh dex
Dialga.
yes but sinnoh
It stands for National PokeDex, and it's the upgraded version of the Sinnoh Pokedex. You get it from the PokeMon Professor (that gave you your starter Pokemon) after completeing the Sinnoh Dex, and beating the Elite 4.
In the Sinnoh dex: Ambipom. In the national dex: Kadabra
There are 210 in the sinnoh dex and 490 in the national dex
you see al the Pokemon in sinnoh
yes
Pokémon Number 152 in the Sinnoh Dex in Platinum is Rotom.
Cranidos in the Sinnoh Dex, Fearow in the National Dex