The one normal form for a name or code a user types: trimmed and in Unicode NFC, so a
decomposed umlaut ("a" + U+0308, as macOS file names and some input methods produce)
reads like the composed one. --level bundesländer typed decomposed was "Unknown geo
level" with a message that rendered identically to the accepted alias. Case-folding is
left to the caller, where the lookup is case-insensitive.
The one normal form for a name or code a user types: trimmed and in Unicode NFC, so a decomposed umlaut ("a" + U+0308, as macOS file names and some input methods produce) reads like the composed one.
--level bundesländertyped decomposed was "Unknown geo level" with a message that rendered identically to the accepted alias. Case-folding is left to the caller, where the lookup is case-insensitive.