The convert cargo to relet function gives you the possibility to change your cargo from generating a freight revenue to instead generating a freight cost.
Open the Cargoes module in the Core section.
Click a cargo in the list to open it in a drawer.
At the top right in the drawer, click More and select Convert Cargo to Relet.
The cargo type will now change to be and the cargo freight will be considered a cost in the voyage profit and loss calculation.
Open the Cargoes module in the Core section.
Click a cargo in the list to open it in a drawer.
At the top right in the drawer, click More and select Convert Cargo to Non-Relet.
The cargo type will now change to be or and the cargo freight will be considered a revenue again in the voyage profit and loss calculation.