In “How Uncool? Repository URIs. . .,” Andy Powell analyzes URI structure in 107 repositories to determine whether their items’ URIs are likely to be persistent..
Here's an excerpt:
So what is an uncool URI? An uncool URI is one that is unlikely to be persistent, typically because the person who first assigned it didn’t think hard enough about likely changes in organisational structure, policy or technology and the impact that changes in those areas might have on the persistence of the URI into the future.