The tag media-centre on ServerFault is spelled incorrectly, it should be changed to media-center.
Edit
When I made this post I did not realize that "center" was spelled "centre" outside of the US. The powers that be need to decide if a retag is warranted. Additionally, a determination should be rendered if US spellings are what should be used for tagging.
That said, maybe I am a dumb/ugly American but I find spelling "center," "centre" jarring. Further the Google Chrome spell checker marks "centre" as incorrect. To some extent these posts probably apply: The Ugly American Programmer and Forced To Write English Syntax Code – Simplicity or Burden.
Probably the best summary of where this thread is headed is contained within this XKCD comic: