The Structures Of Nothing, also known as the inverse versions of Structures Of Everything, are regions accessible by hyperdimensions lower than spacetime. They're still bounded in a specific Hyperdimension and can be supercontained. They work sort of like a fundamental particle, being the stabilizer of everything in their local Structure Of Everyhing.
The Structures of Nothing can also be seen as "portals" to smaller and null-sized objects, and a portable omnipocket in-between null-sized and spatial particles. The size and dimensionality of them is in-between surreal zero and subzero, in which they have no sign but still have a value assigned; and composed of a incomplete form of Dimensional Blueprint Particles.
They're ruled over by many null-sized entities, who live in them.