I think they mean about the medium being readable. Carved graffiti (o paper) is more durable than a CD-R. As this media they're using for the "Very Long-Term Ba

I think they mean about the medium being readable. Carved graffiti (o paper) is more durable than a CD-R. As this media they're using for the "Very Long-Term Backup" hasn't been fully tested yet (we'll need to wait a thousand years for that), they're hoping it will work, but they aren't still sure.