From @MarkusTeufelberger on Fri Jan 20 2017 22:15:01 GMT+0000 (UTC)
An example would be a file that’s hashed with 2 different algorithms or a large file that - if reassembled - has the exactly same content, but has been split up in different individual parts using different algorithms.
Bittorrent suffers from this issue for example, as the creator of the torrent file can choose the block size which in the end leads to different info hashes for the exact same file. This is slightly reconciled in the metalink file format, where one can specify a lot of different sources for the same file. My question is if there’s something similar to metalink for IPFS too, to tell others that 2 completely unrelated addresses actually result in the exactly same content and thus can be used interchangably.
Copied from original issue: https://github.com/ipfs/faq/issues/222