就我个人而言，我会避免使用about-us或about_us，而使用about。

搜索引擎优化专家Jim Westergren在2005年从严格的搜索引擎优化角度对此进行了测试，得出的结论是+(+)实际上是最好的单词分隔符。然而，这似乎并不合理，可能是由于搜索引擎算法的错误。对于可读性和SEO，他推荐使用-(破折号)。

对于最终用户视图，我更喜欢“about-us”或“about us”，而不是“about_us”

更好的利用。- /作为分隔符，因为_似乎不是分隔符。

http://www.sistrix.com/blog/832-how-long-may-a-linktext-be.html

我更喜欢破折号，因为下划线可能在一定程度上被链接下划线所掩盖。文本url主要是为了一眼就能识别出来，而不是为了语法正确，所以保留破折号用于连字符的论点是有限的。

文本URL的准确性很重要的是在将其读给某人时，在这种情况下，您不希望将下划线与空格混淆(反之亦然)。

我还发现破折号更美观，如果这有意义的话。

I'm more comfortable with underscores. First of all, they match in with my regular programming experience of variable_names_are_not-subtraction, second of all, and I believe this was mentioned already, words can have hyphens, but they do not ever have underscores. To pick a really stupid example, "Nation-state country" is different from "nation state country". The former translates something like "the land of nation-states" (think "this here is gun country! Best move along, y'hear?"), whereas the latter looks like a list of sometime-synonyms. http://example.com/nation-state-country/ doesn't appear to mean the same as http://example.com/nation-state_country/, and yet, if hyphens are delimiters/"space"s in addition to characters in words, it can. The latter seems more clear as to the actual purpose, whereas the former looks more like that list, if anything.