As described in my source from this Reddit post in a vertical position, using a mirror and after using a "Braille Alphabet" the word "STON" is created some people mention it can maybe be "STONK" but I don't see that. I have yet to find a sarcophagus with a different code as I've seen many in Ankrahmun and also in Goroma Cults with the same code. If I find a different one I will let you know. Although the Sarcophagus is similar, it isn't exactly 6 dots like Braille. Look at the "S" that is more than 6 dot spacing for example.
With a quick google search of the definitions: Ston is a village and municipality in the Dubrovnik-Neretva County of Croatia, located at the south of isthmus of the Pelješac peninsula. The town of Ston is the center of the Ston municipality. Stonk means a concentrated artillery bombardment.
Image source of the Braille Alphabet: (not supported)