I’ve been keeping track of what I read for a few years now. I used the year (ie. 2006, 2007) as the category to keep the books ordered. When I tried to add a new category with a title of 2008, I got a message that numbers are not allowed in category URLs. Is there any way to change this? I’d really like to still continue categorizing books read by year. (This also affects another weblog I publish.) Thanks!