A Duel Terminal Secret Rare card has all the characteristics of a Secret Rare card (i.e. a glittery image and a silver name), but has the "Duel Terminal" Parallel coating which makes the whole surface reflect, with a much larger dot print on the film than standard Parallel Rares. The coating tends to stiffen the card and when scanned the coating creates a uniform haze on the card. They are currently only available in the OCG.
On the Official Card Database, this rarity is labelled as Secret Rare.