Charge Link (チャージリンク Chāji Rinku) is an unofficial term for several cards that appear in Booster 5: Victory Song of the Overlord.
It is a variation of Square Link that requires the other Z/X to be in Charge (or need to pay the Cost for the ability using a specific Z/X in Charge for "Fighting Strong Wrestler") instead of Square. Unlike Square Link, not all of the required Z/X are vanilla.