If you set STATIC_URL to a static value, then each time you update a CSS file, a JavaScript file, or an image, you will need to clear the browser cache in order to see the changes. There is a trick to work around clearing the browser's cache. It is to have the revision number of the version control system shown in STATIC_URL. Whenever the code is updated, the visitor's browser will force the loading of all-new static files.

This recipe shows how to put a revision number in STATIC_URL for Subversion users.