Nethen Ciclimancy

One of the ancient peoples of Karenth, the Nethen, had a cypher used by their mages, sages and scientists. Only one fragment of this cypher has been found on an old clay tablet. This is particularly interesting to the Order of Eight as it is the only clay tablet found anywhere in the world. At this point, not a single character of the cypher has been identified by Order.
The cypher was used by mages and scientists to encode findings and instructions. This would prevent the information from falling into the wrong hands from written sources.
The Order has not realized that the cypher is more than written. It requires a special lens or set of glasses that have been enchanted with true seeing to understand them. The glasses alone will not allow the user to read them, as the cypher's key must also be known. The cypher is also written in a method requiring a unique key. Whether the key was based on the idividual who wrote it, the document, or by a group of people is also unknown.
Deconstructing the cypher with the glasses and the key is time consuming even for those who are proficient. It requires work to be done on paper to determine the path of the cypher along the key. It's not a simple a-z z-a cypher.
Writing of the cypher requires some knowledge of magic. All members of the Nethen magiocracy, science academies, and the resulting sages were trained first in magic, and as such, have sufficient knowledge to write the cypher.
There exists information in the Karenth to read the cypher, as it was taught widely in the culture. However, each piece of cypher has a key that goes with it, and the key must also be found. As the cypher is magical, magical read language deciphering spells tend to not work for solving the cypher. Since the Nethen culture fell thousands of years ago, much of their work is gone due to the effects of time. That is why the clay tablet found by the Order is so interesting. However, much of the work of the Nethens was done on paper, velum, papyrus, and other organic materials such as starched muslin. Many of the old documents have deteriorated, rotted, or been eaten.