每一个主题的实体一定要有一个标识符。

Each topical entity must have an identifier.

youdao

URL是一个标识符，不指向网页。

The URL is an identifier; it does not point to a Web page.

youdao

例如，在http中uri是一个标识符。

For example, a URI in HTTP is an identifier.

youdao

If you're writing a one line function, whose sole purpose in life is addition, and, clearly, this is about addition, well, then it's, in fact, A reasonable to use a shorter symbol like A, but I do have to specify it's type.

如果你在写一个一行的函数，它唯一的目的是,做加法，显然这是关于加法的，好的，实际上，用一个短的标识符是合理的，像，但是我必须指明它的类型。

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