In a peer-to-peer network of peers which are interconnected for sharing content data, the peers store content files of content data in a file structure comprising a plurality of content folders each content folder containing any number of content files of related content data, and a description file containing both unique identification information and descriptive information in XML format describing the content file or files stored in the same content folder. Requesting peers transmit search query messages which specify search criteria for passage through the network. Peers receiving a search query message compare the search criteria with the descriptive information contained in the description files in each of their plurality of content folders and in the event of there being a matching content folder transmit a hit message including the identification information to identify the matching content folder for passage back through the network to the respective requesting peer.