Spin Edge

A selected edge, spun multiple times (function repeatedly applied).

This command to turns (spins) the selected edges (several can be turned simultaneously) of two adjacent polygons and connects them to the neighboring two points.

Why would anyone need to do this? This way the polygon flow can be altered or poles smoothed (e.g., if five or more edges meet at a single point).

Tip:
If you experience shading anomalies after spinning edges (see image below), switch to polygon mode, select the affected polygons and call up the Change Point Order command, which should solve the problem.