This function is similar to Align Normals. Here, however, the Normals are reversed. If no polygons are selected, all the Normals of a selected object are reversed. With an active selection only the Normals of the selected surfaces are considered.
Several limitations were removed with the introduction of Cinema 4D R19:
This command has the following options:
Normals: If an object has Normal tags with vertex Normals, this option decides if the vertex Normals for the polygons to be aligned should also be reversed or remain exactly as they were saved in the tag.