As everybody is probably already aware, natural stones are rapidly disappearing from the world. This leads to a new problem: Without any stones around, you can't carve runestones, making communication with nearby players very difficult.
I live in an area that's at this point entirely devoid of stones (I need to travel very far to find any). Some distance away, still in the area where all stones have been depleted, I found a finished but only half-claimed palisade; they were clearly still setting up. (I could destroy the palisade very slowly with my ~25 STR.) However, they forgot to put a lock on the gate (or don't have the skills yet). I wanted to leave a runestone inside their palisade warning them that another player could instead craft a lock and put it on their palisade, but...with the area entirely devoid of stones, I had no way to contact them.
For situations like this it would be nice if we had some other way of indirect messaging, perhaps constructing signs or something?