We've got a wiki for our church running on Mediawiki, so the default site-wide copyright notice is the GFDL.
We want to replace that so that we can protect our stuff, and more importantly some of the people who's details might be posted.
First off, what's the procedure for doing this?
Second, what's the effect this has on stuff which has already been added? There was an **understanding** that we would be adding a proper copyright notice when we gotta round tuit, but does the fact that the stuff has already been added with a GFDL notice in effect make trouble for us?