  In renormalization group (RG) flow, the low energy states form a code
subspace that is approximately protected against the local short-distance
errors. We motivate this connection with an example of spin-blocking RG in
classical spin models. We consider the continuous multi-scale renormalization
ansatz (cMERA) for massive free fields as a concrete example of real-space RG
in quantum field theory (QFT) and show that the low-energy coherent states are
approximately protected from the errors caused by the high-energy localized
coherent operators. In holographic RG flows, we study the phase transition in
the entanglement wedge of a single region and argue that one needs to define
the price and the distance of the code with respect to the reconstructable
wedge.
