Treating ij as a single letter in Dutch makes no sense, unless one also treats au, ei*, eu, ou, and ui as single letters. And possibly sch as well. * especial

Treating ij as a single letter in Dutch makes no sense, unless one also treats au, ei*, eu, ou, and ui as single letters. And possibly sch as well. * especially ei as it's the same sound: eis (demand) and ijs (ice) are homonyms.