The concept of border is one of the main categories of spatial semiotics together with concepts of form, place, space, etc. A border is a part of semiotized space that separates larger places with different meanings and at the same time connects their edges. Borders fulfill their semiotic functions and participate in acts of inter-subject communication being included in the plane of expression of various spatial codes. At the same time, the borders themselves can be indicated by means of a particular semiotic system – a demarcation code. This code contains in its expression plane the indexes that help distinguish the borders for whoever moves among them. Therefore, they serve also as signals of possibility or impossibility of movements into different places. The sundry cultural versions of the demarcation code can include the indexes of diverse kinds: pillars, barriers, fences, graphic means, etc. Together with these direct markers of borders, the demarcation code contains also derivative categories: “obstacle, “aperture”, “passage”, “path” and other. They can form diverse syntactic combinations with distinct meanings: “obstacles-on-passage”, “aperture-in-obstacles”, “passage-between-walls”, “path-between-places”, etc. The content plane of the demarcation code comprises different schemas of possible locomotion and manipulations in the bordered space. These schemata are important for planning external behaviour as well as for the internal activities of imagination, spatial metaphors in verbal language, and even logical thinking. So, the means of the architectonic code are involved in various areas of human activity. Obviously, they have a primary significance for architecture, design, and other spatial arts.