A question from Ontario, Canada. Tripstar says: “Underscores vs hyphens in URLs, does it make a difference? my-page vs my_page?”.
It does make a difference, I would go with dashes or hyphens if you can. If you have underscores and things are working fine for you, I wouldn't worry about changing your architecture.
A while ago, I said “we are looking at using underscores as separators” and the reason why we typically never talk about stuff in the future is that gives us the freedom to change our mind and in fact, the people who are working on that project, worked on something slightly different for scoring in the URL, that was actually higher impact and a much higher win.
We might still get around to that, thanks for the ping, I'll try to ask some folks on our Quality Triage Team: “hey can we take a fresh look at this?” but for the time being, underscores are treated as separators, oh sorry, dashes or hyphens are treated as separators and underscores are not.
That might change in the future but that's the way it stands right now.