Following the first Greek grammars or even older sources, there is a traditional and apparently arbitrary order used for cases in most if not all living European languages, e.g. in declension tables. It often starts like this (NGDA):
Other cases usually follow if they’re used, e.g.
- Ablative (abbreviated ‘B’ below)
In modern language teaching, it seems to become more common to group the cases by morphologic similarity to aid memorization. This results in NADG instead of NGDA for German. I’ve seen NAGD for Old English, though. Latin should probably use NVABDG, Russian maybe NAGPDI because Acc forms agree with either Nom or Gen depending on animacy.
How much does similarity of case morphemes differ by language? Is there a logical canonical order of (nominal) cases across (Indo-)European languages?