In languages with singular/dual/plural systems in the noun, if the plural is used in any instances where a set of two objects is designated, the plural may be used with the numeral for 2.
Standardized
Provided the number marking of nouns distinguishes singular, dual, and plural, IF the plural is used in any instances where a set of two objects is designated, THEN the plural can be used on nouns in construction with the numeral ‘two’.
See also #548.