Dutch also has a digraph-which-counts-as-a-letter, "ij". But that doesn't get title-cased internally - there is a city called IJmuiden, not Ijmuiden.
data:text/html,<div lang="nl" style="text-transform:capitalize">ijmuiden
In Firefox, this displays correctly as "IJmuiden" (thanks to the lang attribute; without that, it would show "Ijmuiden").