What does the circle with a line through it mean. It has appeared above the mileage data on the dashboard on my Corsa?

What does the circle with a line through it mean. It has appeared above the mileage data on the dashboard on my Corsa?
In computer technology, a circle with a line through it typically denotes a zero, as opposed to the letter 'O'. This is done to prevent confusion. Not sure if this is what you where looking for