The "multiple messages of increasing complexity" concept was one of the proposals. The simpler stages are usually written out in as many languages as possible.

The "multiple messages of increasing complexity" concept was one of the proposals. The simpler stages are usually written out in as many languages as possible. https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warning_messages https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin... Another proposal was to leave no marker at all. (Or to bury the first marker.) There's an argument that anything special on the surface will only make people curious about the site.