Contingent orders are the same as related trade orders.
Several types are available:
If Done (slave), where a slave order only becomes active if the primary order is executed.
One Cancels the Other (O.C.O.), where the execution of one order cancels the other.
Three-way contingent orders are also available where two orders are placed if (If Done) a primary order is executed.
These orders are themselves related as O.C.O. orders, allowing both a stop loss and a profit taking order to be placed around a position.