In German, 'ß' is definitely not just a ligature of 'ss'. Consider 'Masse' (mass) vs. 'Maße' (dimensions). Uppercasing these words will necessarily produce am

In German, 'ß' is definitely not just a ligature of 'ss'. Consider 'Masse' (mass) vs. 'Maße' (dimensions). Uppercasing these words will necessarily produce ambiguity. It would be equally tempting -- and wrong -- to treat the German characters 'ä', 'ö' and 'ü' as ligatures of 'ae', 'oe' and 'ue'. They're pronounced the same, and the latter forms commonly occur as substitutions in informal writing, but they also occur in proper names, where it would be incorrect to substitute them with the former. However, if you want to sort German strings, 'ä', 'ö' and 'ü' sort as 'ae', 'oe' and 'ue'.