- p31: Definition 2.9 is incorrectly attributed to "Bradford,
Butler and Chmutov [8]". The correct attribution is
"Chmutov [16]".

- p59: The statement of Item (2) of Proposition 3.27 is incorrect. What is actually shown is that if $G$ is an orientable ribbon graph, then $G$ is bipartite if and onlyif $G^{\tau(E(G))}$ is orientable.