The only case is with XY-Scatter charts. These assume that the second
column (Y) is a function of the first. If you choose marks only and no
line, then the (x,y) points will be shown in their proper places
regardless of order of the x points in your worksheet.

However! COntrary to other chart types (e.g. column chart), which space
all data points evenly across the horizontal axis, here the placement
of the marks will depend on the values of x along the x-axis.

HTH
Kostis Vezerides