It can function as a check in the way constitutionalists want to think of checks. It's an interesting idea, but I don't know if it'd work well in practice. First, people would need to settle on a common set of a navigation commands across sites. Second, most people use the location bar in their browser as the command line shortcut to get around a site. My inner librarian wants this book.
Classification affects perception.
Consider that some of the WebLog lists consider this site to be a 'general' WebLog, while others classify it as a 'technical' site. Sabren's written a tutorial and some sample code for making search engine friendly URLs for PHP-driven sites . It is sometimes fragile, and can be remarkably easy to break. Metajournals opened a contest for redesigning their site . In the Weblog and Glossary world, these things map easily into columns in a database table, or instance variables in an object.