The Keramin Carving

The war of conquest that would eventually capture Dus A Thanal and make it in to the first of the non-original Lordships was launched for a lot of reasons. The nascent Diarchy wanted a war to bind the two halves together against an external enemy, there was a shortage of deep water ports, the wars between the Kingdom and the Theocracy had created a lot of skilled fighters, the peace had made them unemployed and the leaders were anxious that they didn't become bored, various other reasons. But fear of the Doppelgangers, the natives of Dus A Thanal, was very much one of them.
Records of that time ar a little sparse, but the prevailing wisdom is that the Doppelgangers were winning. The Diarchy simply didn't have the internal resilience to fight the psychological warfare the Doppelgangers waged and the two armies inexpertly melded together were easy prey for infiltrators.
Which is why the Keramin Carving came as such a surprise and is the subject of so many conspiracy theories. What's certain is that a scouting party discovered that the Doppelganger village was abandonded and cleared out, with only a large rock in the middle, carved with one simple word - Keramin. At this time knowledge of the Doppelganger language was even more limited than it is today and the message was not understood. The village was occupied, and fortified, and General Tomas ver Heek became the first Lord of Dus A Thanal (the office of Topicarch was created later).
Over the succeeding years it became clear that the Doppelgangers had not fled, or not all fled at least, and though they live hidden in Dus A Thanal there have been some contacts etween known Doppelgangers and the authorities and, early in these conversations, it was asked what "Keramin" means. The Diarchy was informed it means "We Surrender" and that remains the official word to this day. The Doppelgangers surrendered.
But...
But who knows how many of them have infiltrated Thanali society for who knows what reason.
But they seem to have some way of communicating amongst themselves at a distance.
But they make plans spanning generations and centuries.
But as far as anyone can tell they refer to the surrender of the Northern Duchies as the "Sin gemaris" which doesn't seem to have the same root as Keramin.
But skill at making subtle threats that aren't immediately recognised as such is a marker of high honour in their society.
The problem is that there's only their word for it that "Keramin" means "We Surrender" not, for example, "We are about to embark on a long term plan that will eventually destroy you". And until those "buts" can be cleared up, the Keramin Carving will always be a source of suspicion.