A quad is commonly used in the 3D graphics world to mean a rectangle (https://www.selfcad.com/blog/quads-in-3d-a-complete-guide https://www.selfcad.com/blog/qua

A quad is commonly used in the 3D graphics world to mean a rectangle (https://www.selfcad.com/blog/quads-in-3d-a-complete-guide https://www.selfcad.com/blog/quads-in-3d-a-complete-guide), so the idea is that we go "kubelet" -reinterpret-> "cubelet" -flatten it-> "quadlet".