A long time ago I enabled the WordPress permalink functionality so that the links for my blog articles were somewhat human readable.  I used my own custom format, /%category%/%year%/%monthnum%/%day%/%postname%/.

Awhile ago I began regretting that format because if I changed the category of the article then the URL would change and any bookmarks to that article would be broken.

Today I started reorganizing a lot of categories and decided it was time to bite the bullter.  I changed the permalink format to the standard /%year%/%monthnum%/%day%/%postname%/.   What was so impressive is that the old URL’s still worked, they redirected to the new URL.  WordPress rocks.