Here is a brief graphical summary of the impact when using a flip arrow control. Single arrows rotate a family 180° and a double arrow mirrors the family around the relevant axis. Note: Horizontal and Vertical single arrows have an identical affect, irrespective of axis.

In this example: The Blue symbol is the original and the Red symbol is the flipped version

© Copyright Reserved by Michelle Louw (Excerpt from My speaker notes at National Revit Technology Conference 2008.)