Jepessen indicate the position at which to reduce speed on an arrival with a "X" and an arrow pointing to it stating the speed to be flown.
However, there also seems to be a small 'shaded square' at each of these points, starting from the middle of that "X", in the direction of flight.
Any ideas as to what this square is for....???
(Couldn't find it in the chart legend)
Here's hoping someone knows what I'm talking about...
Patches