A field must be navigable. The MapDimensioning names the cartographic operation through which a corpus makes itself traversable: not by reducing complexity, but by encoding it in navigable form. In the Socioplastics architecture, the 3,000 nodes are not a flat list. They are a multi-dimensional space. But the dimensions are not self-evident. They must be mapped. The MapDimensioning makes this explicit. It identifies the axes: the scalar axis (node number as magnitude), the thematic axis (cluster as topic), the temporal axis (stratum as duration), the disciplinary axis (core as field), the operational axis (mode as function). These axes are not given. They are constructed. The map is not a description of the field. It is an operation on the field. It transforms the corpus from an unnavigable mass into a traversable space. The MapDimensioning is not about making the field simple. It is about making the field complex in a legible way. A good map does not remove detail. It organizes detail. Node 2505 places this concept in Core IV because map dimensioning is a field condition, not a conceptual content. It is the operation that makes the field usable. Without this concept, the corpus is a labyrinth. With it, the corpus is a territory.