Some languages have retained specific forms when using a number equal to 2, or betwween 2 and 4, differing from the plural used with higher numerals.
Among languages N++ addresses, I'm aware of this issue in Arabic, Hebrew, Maltese, Tagalog, Slovenian and Russian.
Is this list accurate?
Are specific entries in the localisation files required? This would imply defining whether any given language uses dual forms, and the numeric ranges it applies to.