It's useful to create an "identifying yourself" subcase and spec it out as if it were a standalone use case, then incorporate it by reference into the main use cases. 应当创建“标识自己”子用例并将它指定成类似于独立用例,然后通过在主用例中进行引用来合并它。
The main distinction between "subset" and "uses" is that a "uses" relationship applies when a use case is a subcase that is also a standalone use case. “子集”和“使用”之间的主要区别是当用例既是子用例也是独立用例时应用“使用”关系。