incrediBILL - 2:35 am on Nov 24, 2012 (gmt 0)
given that the default style for anchor text is underlined, underscores in URLs are a poor usabillity practice.
i.e., is that an underscore or an underlined space character?
Usability? How so?
People either click it, bookmark it or select and copy it, neither action requires knowing if it's an underscore or a space.