Hi Alex,
Nick is correct in his interpretation, Robert's Rules of Poker (RROP) rule attached:
7. A card discovered faceup in the deck (boxed card) will be treated as a meaningless scrap of paper. A card being treated as a scrap of paper will be replaced by the next card below it in the deck, except when the next card has already been dealt facedown to another player and mixed in with other downcards. In that case, the card that was faceup in the deck will be replaced after all other cards are dealt for that round.
This rule is the same in Ring/Tournament. To use the 'Turn Crad' would be incorrect, you are still issuing the flop as normal, the boxed card has no bearing on the stub, it is (treated as) a scrap of paper and you would then burn and turn for 4th street as normal.
Regards
Stuart