that achieves the design goal $(n,k,d)=(10,7,9)$. Specifically, each newcomer can access $d=9$ helpers and any $k=7$ nodes can be used to reconstruct the original file. At the same time, [@dimakis2010network] also provides RCs to achieve the design goal when $(n,k,d)=(10,7,5)$. However, those RCs can be an overkill in this scenario of $(n,k,d)=(10,7,5)$ since any RC construction in [@dimakis2010network] that can achieve $(n,k,d)=(10,7,5)$ can always achieve $k^*= d=5$. As a result, even though the high-level design goal is to only protect against $10-7=3$ failures, the RC in [@dimakis2010network] cannot take advantage of this relatively low protection-level requirement since it always has $k^*\leq d=5$, which is strictly smaller than the design requirement $k=7$.

Note that the above observation does not mean that the system designer should never use the RCs [@dimakis2010network] when the design goal is $(n,k,d)=(10,7,5)$. The reason is that these RCs with BHS have many other advantages that may be very appealing in practice, e.g., some very efficient algebraic code construction methods [@shah2012interference], allowing repair with $n-d$ simultaneous failures, and admitting efficient collaborative repair when more than one node fails [@shum2013cooperative]. The fact that $k^*\leq d$ for any RCs in [@dimakis2010network] simply means that when the requirement is $(n,k,d)=(10,7,5)$, the 