Number of nRF51822 high drive pins

The nRF51822 Product Specification says that "Maximum number of pins with 5 mA high drive is 3."

Does that mean that you can only configure 3 pins as high drive, or could I (for example) configure all pins as high-drive output, as long as no more than three of them source or sink 5 mA at any time? (And is it really 5 mA per pin, or 15 mA total? Could I have 5 pins all sourcing 3 mA each?)