Should the orange tab on the back remain closed or opened during use? What's the purpose of that tab?

Should the orange tab on the back remain closed or opened during use? What's the purpose of that tab?

During sterilization, the orange tab on the back of the Nuvita 1085 sterilizer must remain closed. After sterilization, open the tab and place the sterilizer in a vertical position. In this way, excess water will be eliminated. This allows to keep the product closed and consequently sterile the objects inside it until they are used.