Very pertinent, good eye. If they are suitably random then this scheme seems to check out, but you're going to need some barbed wire and some inspiration from

Very pertinent, good eye. If they are suitably random then this scheme seems to check out, but you're going to need some barbed wire and some inspiration from these https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warning_messages https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin... on anything that can generate v7 IDs.