DC++: how to avoid duplicate download ?

i am downloading a lot of comics from a few hubs and from different users and lets say im downloading punisher issues and they are in one directory structure at user no.1 and in a different directory structure at user no.2 but its a completely the same file, lets say that both users have downloaded the original file using torrent from another source (e.g.) and the DC++ will download the same file twice or even more then twice if the users have them locally in multiple directories (unsorted etc.) and basically since im downloading entire directories, i have a lot of duplicate files......if these were pictures i wouldnt mind but since a comic file can go up to 100mb or more its a waste of bandwidth and disk space.
how can i avoid this ?
i am not familiar with hash tags in DC++ network, are they unique across the entire DC++ network or just on the level of a hub or even only on the level of a user ?
i do not want to search for single issues and download them one by one because its a lot of work and very tedious.
download folder is shared automatically so DC++ can see that i already have a specific file and should simply skip it if its already there.

please help me with settings if there are any.

thanks!