Multiple redirection is utilized to separate the various levels of abstraction in the schema of associating resources with blog embeds and links.

At the lowest level, an author writing a blog entry with an embedded video will simply add the shortcodes for [mirror-1], [mirror-2], etc., without needing to know anything about how the mirrors are configured.  Typically this will be done with Composite Shortcodes.

At the next level, the blog administrator (or the network administrator acting for the blog administrator) will set the  [mirror-1], [mirror-2], etc. to point to the appropriate resources by Repository ID, whether knowing or not knowing the current actual servers.

If/when a change in servers or other configuration change is made, no posts or pages need be changed; the shortcodes and IDs make the change automatically and transparently.

For example, a multisite operator may designate four mirror servers, giving them Virtual IDs of [video-server], [fast-server], [bulk-server], and [local-server].  The owner of a blog on the multisite may chose to mirror only on [video-server], and [bulk-server], independent of their actual location.  Meanwhile, the multisite operator can change the hosting of [bulk-server] (cloning the file structure, of course) transparently to the individual blog owners.