In pedestrian navigation, navigators are free to choose any passable way. Because of this characteristic, accurate route instructions are important when navigating from waypoint to waypoint. In this paper, a theoretical framework is described for dealing with position uncertainty in pedestrian guiding systems. Stages of closeness are defined based on the topological relation between the navigator and a waypoint. These stages of closeness allow for refining route instructions and, therefore, leading to more accurate navigation and increased efficiency of the system.