INA232: What does Vos_b IN– bus offset Voltage mean?

Tool/software:

On the front page of the datasheet it is says 50-µV offset (maximum), which sounds reasonable.

I the electrical characteristics there is a line specifying

       Vos_b IN– bus offset Voltage = ±10mV max

but what does that mean?

ADC input range is specified at ±20 or 80mV so 10mV offset sounds very strange.