Backward capacity time fence


In the master planning form, there is a field “Backward capacity time fence”. Can someone tell me what the purpose of this time fence, and give me some example to help me how to use this time fence please?

Many thanks,

It looks backwards from teh requirement date to find capacity, but only looks backwards the time in teh time fence, then starts looking forward. So we have a requirement on 30/07/12 and a backward time fence of 30 days, it looks backwards to 01/07/12 for capacity then plans forward from 30/07/12 if capacity does not exist. If infinite it is naturally irreelvant.