Moving UPLOADS directory

I want to keep my UPLOADS directory outside the WP_CONTENT_DIR, and I wonder whether the info in the codex page is wrong or WordPress is not really prepared to have the UPLOADS content somewhere else:

In the codex page for editing wp-config.php, it shows as example:

define( ‘UPLOADS’, ‘/blog/wp-content/uploads’ );
This path can not be absolute. It is always relative to ABSPATH

Now, judging by the previous lines

define( ‘WP_PLUGIN_DIR’, dirname(__FILE__) . ‘/blog/wp-content/plugins’ );

It seems blog is the ABSPATH, so a relative path to it would start with /wp-content, and NOT with /blog.

Also, I if you start your path with a slash, you get double slash in your images urls.

Can anyone clarify?

Thanks.