BitTorrent file like functionality with magnet links

One of the competitors of DC is BitTorrent. With BT, one is able to supply torrent files that contain links to multiple files or sets (among other things). (Yeah, over simplification perhaps.) As torrent files contain knowledge about multiple files, people have been discussing the possiblity to do similar things in DC, and especially with magnet links. However, there is a huge problem; magnet links point to content, rather than “files”. That is, you cannot say “this magnet link point to file a, file b and file c”, but instead you say “this magnet link point to content a”. However, “content a” is not specific to one file, but it can also mean an entire set of files. E.g., the entire selection of vacation photos or the entire Ubuntu source code collection. The “only” problem with that is that clients need to be able to know how such collections’ hashes are calculated (by combination of hashes or whatever that is the protocol). One might of cou ...