I just changed the URL of one of my posts from

>http://2011.denmark.wordcamp.org/session/theme-frameworks-trends-og-standardisering/

to

>http://2011.denmark.wordcamp.org/session/wordpress-themes-mere-end-design/

Now, if I go to the old url, I get redirected to the new one. This is great of course!<br />...But is this a feature of WordPress, or what's going on here?

Does WP keep track of a post's URL history, providing rewrites/redirects for former URLs?<br />Looking at the response header I see WP is sending out a SEO friendly 301 redirect... Yes!?<br />I thought I'd have to set up those redirects using rewrite rules in my `.htaccess`, so I'm curious to know how it happens that WP is giving me my new URL when I type in the old one.

Any light on how WP handles this would be appreciated.