Protect yourself, protect the people
The Alńa runes are an ensemble of magical, invisible runes. They have two main uses. First, they confer magical properties to two object or place they are placed on. For instance, a sword enchanted with a fire rune would burn when connecting with the target, or a protection rune on a pond would keep away spirits. Second, they can be use as a mean of communication betwen mages. An alńy casts it on an object, usually a house or a tree near a village, so that other alńe can read it, for instance, to know if people inside are friendly. Any pointy object can be used to carve a rune. It does not need to be sharp, since it should not make contact with the surface of the object to write on (in order to not leave physical traces). The alńy does most of the work, a spiritual incanalation of magical energy into the carving tool. Most mages use the first small, easily maneuverable item they find around, usually twigs. Some alńe have a dedicated item they bring along for this work. Master cravers use magical wand they enchanted themselves for maximum power and efficiency.
Communicating with the Runes
In the Dark Lands most people deem sorcerers and witches, collectively called alńe, a necessary evil: they harness the power of magic just like demons, but use it to fight darkness and help people. They are scary, travel and live alone in dangerous regions and are said to be able to wipe out an entire village with their enchantments. Because of this, people react very differently when an alńy knock at their door, especially when they don't need it for curing illnesses or casting fertility spells on the house or the field. Some pretend to not be home, others yell insults and threats, others invite them in politely, but are afraid. The alńa runes contain a basic set of words easy to cast and read, as "friend" or "enemy" for houses and "stay away" or "go in" for villages and places. These words do not have a magical effect, but are easy to find by magical means, so that other mages can easily detect them. An alńy always look for runes of a predecessor near a place of interest before deciding what to do. If they reach a village in the evening, but the runes advice to stay away from it, they can choose to spend the night in a near pond. Since non-magician can't read magical energies, they will not be able to detect the enchantment, and no alńy will reveal their presence to them. The runes are a protection for both the alńe and the people: they protect the mage since they guide them in choosing wisely, but they also protect the people, since a harmed mage can bring absolute havoc onto the village.