the previous naming tan1, tan2, normal was non-intuitive and very confusing. It was not practical to maintain backward compatibility but all tutorials and example refineMeshDict files have been updated to provide examples of the change.
Reference: Duisburg Test Case (DTC) el Moctar, O., Shigunov, V., Zorn, T., Duisburg Test Case: Post-Panamax Container Ship for Benchmarking, Journal of Ship Technology Research, Vol.59, No.3, pp. 50-65, 2012