Each concept here is mapped to its prerequisites — the ideas you'd need first to understand it — all the way down to four foundations: Space, Time, Energy, Pattern. Click any prerequisite to drill down, or scroll for the chain graph.
A boundary mark is a physical or abstract indicator that occupies space, marking the limits or extent of a defined area, such as a line, sign, or other visual or tactile marker.
External reference — all senses of the word “boundary mark” on Wiktionary. This atlas concept maps to only the slice of meaning relevant to the prerequisite graph.
Trace. Question. Emerge.