 Due to the initial simplicity of the "S ####" format, plates in the Federated Malay States (FMS) (Perak, Selangor, Negri Sembilan and Pahang) and Unfederated Malay States (UMS) (Johore, Trengganu, Kelantan, Kedah and Perlis) originally follow distinct series of state identifiers which may use one or two letters (i.e.