Perfect code in graphs not distance-transitive

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Why do we consider a graph as distance-transitive graph when we talk about a perfect code in a graph? Indeed, When there is a non-trivial perfect code in a graph, is the graph a distance-transitive or distance-regular graph? Is there a graph which is not distance-regular but there is non-trivial perfect code in it?

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Classical coding theory studies perfect codes in Hamming graphs. Since Hamming graphs are distance transitive, it is reasonable to consider perfect codes in distance-regular graphs.

Next. some of the basic results, such as Lloyd's theorem extend very naturally to distance-regular graphs. This again provides evidence that it is reasonable to consider perfect codes in these graphs.

There are regular graphs that are not distance-regular but do have perfect 1-codes. If $A$ and $B$ are the adjacency matrices of a graph $X$ and its complement, the matrix $$ \begin{pmatrix}A&B\\ B&A\end{pmatrix} $$ is the adjacency matrix of a graph with a perfect 1-code of size two (in most cases). (There are many other examples, but these are the first that come to mind.)