pluralCategory

The English rule, |n| == 1 → PluralCategory.ONE.

CLDR's English rule is i == 1 and v == 0, which puts 1.0 written with a fraction digit into other. That distinction needs the formatted string rather than the number, which this signature does not carry, so it is not drawn.

The magnitude is taken because CLDR defines its operand n as "the absolute value of the source number": -1 is one, so pluralize(value: -1, one: "item", other: "items") reads "-1 item" rather than "-1 items".