20. The method of claim 18 , wherein the associated metadata is at least one of: a plurality of patches created by the PAP from each MMDE, the at least one signature generated by the SG to each MMDE, and the concept matched for each MMDE based on the signatures generated by the CP.
18. The method of claim 11 , wherein the AP is a patch AP (PAP) that is configured to extract items in the form of patches from the received MMDE.