The use of nuclear fission to generate power results in waste materials that can be hazardous to people and to other life forms, particularly in the first few hundred years after the wastes are created. There is a worldwide consensus that the management of these wastes must not place undue burdens on future generations. In some countries, the opinion is openly stated that those who enjoyed the benefits of the power that produced the wastes must be responsible for taking care of the wastes. Opinions diverge when discussion turns to the question of whether the wastes will always be a liability or eventually become an asset.

Another point of consensus is that at least some of the radioactive wastes should be disposed of by a method that securely isolates them from the accessible environment of plant, animal, and human life until the radioactivity levels have decayed to levels similar to those found in natural environments. Different countries take different positions on the details of what the activity level might be that constitutes the end of moral responsibility for the wastes, but the general position is basically the same worldwide. I explore some concerns about how disposal containers and waste repositories might be marked with suitable identification. In particular, I examine whether the message to be conveyed by the markings needs to change with time and with the entity examining the objects, and whether we can design markers that will convey this potentially variable message.