This attribute performs a check to see whether the word shows up specifically in any of these elements.
该属性执行一个检查，看单词是否特定出现在这些元素的哪一个中。
2
That is, an attribute name can have a collection (or list) of associated values; a word item could, for example, have multiple-definition attribute values.
也就是说，一个属性名可以有一个相关值集合(或列表)；例如，一个词项目可以有多重定义的属性值。
3
Individual elements of the attribute list can either be a word or a word followed by possible parameters for the attribute in parentheses.