So you know what is a file format the we would be able to Reed 100 years from now. CSV, json even fits (that is 30 years old now). If you don't know the original way it was created you know what each field I supposed to mean (if done well). Otherwise you look at hex decoded data with no way if knowing how to decide it if you don't have tha spec on how and why this was encoded. Msgpack and cbor are cool but in 100 years there is no way to decide it.