  Analysis on fractals is a growing field, with hints of potential for
widespread applicability across all of STEM. One of the most heavily researched
type of fractals are the nested fractals, fractal shapes defined by virtue of
being made of smaller copies of themselves. In this paper I introduce a simple,
universal numerical system for describing all self-similar nested spaces. For a
nested space made of $N>1$ smaller copies of itself, the location of all points
can be specified using the double shift space $\lbrace 0,1,...,N-1
\rbrace^{\mathbb{Z}}$, endowed with the appropriate nested topology.
Connectivity rules are established to fully define the topology of the nested
space, and immediate consequences are investigated using the numerical system
defined. I introduce the numerical system and demonstrate how it unifies
previous existing works under a single, simple framework, to argue for its
adoption as standard in discussions of nested fractals.
