This feature is only applicable to the past participle, when used as the main verb of a composite passive. In that function, it agrees morphologically with the subject in gender and number. Since the Gender distinction is irrelevant in the plural, two features can be combined into one, taking the values nonneutral, neutral (implying singular) and plural. (In finite forms, Number is obselete in Swedish, having been dropped even in formal written language fifty years ago).