I used to think the choice of using dashes vs underscores to separate words in an URL was simply a matter of personal preference. Nothing more than a religious choice.

Personally, I preferred underscores because I felt dashes intruded upon the words while underscores stayed at the bottom out of the way. So much so I had originally made that the default URL scheme in Subtext for friendly URLs and was using that myself.

It wasn’t till recently that I learned this debate has already been resolved. Years ago.

I wouldn’t say resolved really. Just that, there appears to be a really good reason to choose dashes over underscores. Apparently, Google sees the dash as a word separator, while the underscore is perceived to be part of the word. Something to do with being able to search for C++ style constant variables SUCH_AS_THIS in the title of a post.

The question is, does this still apply today? Does iteven matter?

To be on the safe side, I’m falling in line for now. Or rather, in dash. What are your thoughts?