avoidStruts

Adjust layout automagically: don't cover up any docks, status bars, etc. Note that this modifier must be applied before any modifier that changes the screen rectangle, or struts will be applied in the wrong place and may affect the other modifier(s) in odd ways. This is most commonly seen with the spacing modifier and friends.
Adjust layout automagically: don't cover up docks, status bars, etc. on the indicated sides of the screen. Valid sides are U (top), D (bottom), R (right), or L (left). The warning in avoidStruts applies to this modifier as well.