My searches about the "Trie" have led me outside by the Valleys of Natisone, until you get to Cividale del Friuli, the ancient Forum Julii, a little town founded by Julius Caesar in 50 BC, with the aim to strengthen and consolidate the Roman presence in this area.
Somebody told me about the possible presence of a Tria in a church of this town, but, initially, I was not able to locate it.
Then, when he had lost all my hopes, I finally found it, outside of the church of St. Maria in Court, now desecrated, near the Cathedral of Cividale, at 50 meters from the National Archaeological Museum.
Is outdoors, at the entrance, and precisely on the upper stone of the wall, on the right. (I purposely wet the surface, becouse the incison i really worn)
On initial observation, this stone would seem an integral part of the wall enclosing the current, because the little stone where has been made the tria, as to the type and form, is very similar with the other one on the wall.
However, knowing that the church was made in 1590, I think that these stones have been relocated, and maybe originally formed part of a wall or of a pavement, and then were partially re-used on this wall.
Now I have reached the final conclusion that this symbol, the Tria, identify a particular houses called "Ospitale", like a monastery, where for the Templars could find shelter, protection and restoration, during their travels to Jerusalem.
I can say with certainty that this Tria in particular, being in a medieval town like Cividale del Friuli, is a evident identification of an Ospitable, and it must be located where, after in 1590, have been built the church of St. Maria in Court.