The order types used in Synthetix perp v2 are Delayed Orders. All polynomial perp exchange processes are carried out through these orders.
Delayed orders are similar to next-price orders, but with a time delay. Instead of executing an asynchronous 'next-price' order after a semi-arbitrary Chainlink price update, we allow the executor (trader or keeper) to fill the order after a specified amount of time has passed, in addition to a price update.
For instance, if the specified delay is 30 seconds and a price update occurs 10 seconds after the order submission, a keeper can still execute the order, or they can wait for the 30 seconds delay to pass before executing the order.
Front running risk is eliminated
Reduced fee
To read more on orders:
Trading GuideStandard Order