The German Sharp S or Eszett does not have an uppercase equivalent. Instead when `ß' is converted to `SS'. The conversion of `ß' to `SS' requires a special rule, and increases the length of a word, thus disallowing inplace case conversion. Furthermore, my general rule of converting all words to lowercase before looking them up in the dictionary won't work because the conversion of `SS' to lowercase is ambiguous; it can be `ss' or `ß'. I do plan on dealing with this eventually.