Following Trail Signs- My blog Debute

rocks, strings, foliage, branches, or hack signs on tree trunks that mark the designated route.

Trail signs are a way to leave a message so another group can find or follow you in the woods. These can be made using sticks, stones, or other available materials and should be placed where they can readily be seen by those whom you want to follow you.
It is important when making trail signs that any wood or plant materials that you use that are “dead and down,” and before moving any item, you make certain you are not directly disturbing any visible habitats or creating opportunity for excessive erosion or other dangerous situation.