Select > Convert Selection > To Contained Edges
 
 
 

Changes the current selection to any polygon edges that can be selected depending on what components were originally selected.

For example, if you have a polygon mesh comprised of four-sided polygons (quads) with several vertices selected and then choose Select > Convert Selection > To Contained Edges, only the edges that have two selected vertices are selected.

TipMany of the convert selection features are available from the context sensitive polygon marking menu when you press + whenever a polygon component is selected.