Selecting Port Ranges for FasTrack on the n700

Can anyone point me to something that specifies how to correctly select the port range when adding a new application rule for QOS on the N700?  For example, adding League of Legends or another game to the list.  A general web search seems to suggest that port selection is a device/app-specific issue, but the manual provides no information in this regard.

I know that you have to get that information from the game developer.