Was reading Stranger in a Strange Land recently and Heinlein describes a similar system developed for handling the volume of mail addressed to the Man from Mars

Was reading Stranger in a Strange Land recently and Heinlein describes a similar system developed for handling the volume of mail addressed to the Man from Mars. https://archive.org/details/StrangerInAStrangeLandRobertAHeinlein/page/n181/mode/2up https://archive.org/details/StrangerInAStrangeLandRobertAHei... (pg 183)