What Is the Idea Behind the Clay Envelope?

The clay tokens would have been a standardized shapes and sizes that are ultimately the precursors to the first written numerals. The imprints on the out side of the clay envelope tell you what is stored within. To get at the contents of that envelope, you would have to open it in a way that could be detected. So kind of analogous, like the wax seal on e, on the envelope that, you know, you can tell if it's been broken.