How to Configure and Test a Non-US Keymap on Haiku
Set the physical layout, locale, compose behavior, and application expectations without confusing key mapping with text encoding.
Open Keymap preferences and choose the layout matching the physical keyboard, then test modifiers, dead keys, compose sequences, punctuation, and shortcuts. Set Locale preferences separately; keyboard mapping and language/number formatting are related but not identical.
Use the on-screen representation to locate mismatches. Save a custom keymap under a new name instead of overwriting the supplied map, and keep a known-good layout accessible if the login environment changes.
Test Terminal, a native text view, WebPositive, and any cross-platform toolkit application. If one app differs, report its input method/toolkit path rather than changing the whole system to compensate.