What is the meaning of the term PITCHING used in civil construction or fencing construction.?

Can any one please tell me the meaning of PITCHING or PITCH used in civil construction or construction of wire mesh fencing. The meaning of the term %26amp; where can i find more solutions on pitching.|||Pitch is simply tar. I%26#039;ve seen plenty of pitched flat roofs and pitched wooden fencing, but not pitched wire mesh. I guess you could pitch some types of metal wire for weather protection, but would have thought the common plastic coating was much less trouble.