There is a small snag with the convention. Ships are filed under 'Ship Name (year)' so that we can distinguish between several ships of the same name. Your example for Agincourt (####) would lead to a muddle. For example, in the case of SS Potsdam (1908), which sailed in 1912, should the category be called SS Potsdam (1912), or SS Potsdam (1908) (1912) or what? I think your system needs a rethink. As a footnote I think the year should be in ISO form, i.e., YYYY-MM-DD, so that the sailings will automatically be sorted in chronological order. What about it?