Flip objects top / bottom to their upside down image. Because calculations must be made to find the center of the objects to be flipped, it is strongly recommended that drawings be projected before using this operator.
Example
We begin with a map of Europe in Orthographic projection. The area representing Italy has been selected. Next, load the Transform toolbar with
[selection] Flip Vertically
and press Apply. This is a command to flip Italy left / right to its mirror image.
This command is most frequently used in CAD-style editing of non-geographic data. It is shown here in a geographic setting to make clear its effect.