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\begin{document}$$n,d,w \in \mathbb {N}$$\end{document}, let A(n, d, w) denote the maximum size of a binary code of word length n, minimum distance d and constant weight w. Schrijver recently showed using semidefinite programming that A(23,8,11)=1288\documentclass[12pt]{minimal}
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\begin{document}$$A(23,8,11)=1288$$\end{document}, and the second author that A(22,8,11)=672\documentclass[12pt]{minimal}
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\begin{document}$$A(22,8,11)=672$$\end{document} and A(22,8,10)=616\documentclass[12pt]{minimal}
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\begin{document}$$A(22,8,10)=616$$\end{document}. Here we show uniqueness of the codes achieving these bounds. Let A(n, d) denote the maximum size of a binary code of word length n and minimum distance d. Gijswijt et al. showed that A(20,8)=256\documentclass[12pt]{minimal}
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\begin{document}$$A(20,8)=256$$\end{document}. We show that there are several nonisomorphic codes achieving this bound, and classify all such codes with all distances divisible by 4.