Mark Charm
From Pixelmon Wiki
A Mark Charm is an accessory. It is not an item; rather, it can be seen directly from the player's inventory.
It can be obtained by completing the Kantonian Zapdos legendary bird quest obtained from villagers.
This item increases the chance of catching a Pokémon with a mark. Most marks have a rate of 1/50 or 1/100. With the mark charm, this becomes a 3/50 or 3/100.
The command /markcharm
can also be used to obtain the charm through commands.