Avoids decision ruling out hard borders (5)
I believe the answer is:
edges
'borders' is the definition.
(I know this)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for edges that I've seen before include "Boundaries of a surface" , "Outer limits" , "Sharpened sides of blades" , "Des, e.g. (anag.)" , "Bounds" .)