We should start thinking more seriously about long-term preservation of digital data in general, and I think that one thing that would help a lot is to design our storage (not transmission) formats to include a detailed human-readable description of the format in its headers. Basically just a blob of text, not compressed in any way, something that would be immediately visible and parseable if you inspect the raw data. Depending on how detailed the spec is, this would be an overhead on the order of tens of kilobytes to a few megabytes - for storage, this is negligible, while the long-term benefits are clear.