Normally an underline will lie behind
the text. You will
only notice this if you have set a negative offset from the text as
described below, and neither the text nor the underline are solid
black. In such cases you may use this function to make the underline
appear on top of the text instead of behind it. This function also
allows you to strike-through
outlined or differently coloured
text. Turn this function on/off by clicking on the icon.
