Step-by-step guides on what to do in certain situations.
Removing a Spam Page
First, block the spammer so that it (or, rarely, he or she) can't do any more damage to the wiki. Set the time to "indefinite". Be sure to check the boxes "Prevent account creation", "Prevent user from sending email", "Prevent this user from editing their own talk page while blocked", and "Automatically block the last IP address used by this user, and any subsequent IP addresses they try to edit from" (and, if it's an available option, "Prevent logged-in users from editing from this IP address") in order to reduce further damage to the wiki. Set the reason for blocking to "Spamming links to external sites".
Second, protect the spam page so that only admins can edit it. Set the reason to "excessive spamming". This stops future spammers from using the same page title.
Third, delete the spam page. Set the reason to "excessive spamming".
Fourth, delete the spammer's User and User Talk pages, if they were created. Set the reason to "excessive spamming".
Fifth, look in the "Recent changes" page for accounts created at the same time as the spammer's account, and block them as well. Leave "Prevent user from sending email" unchecked, just in case an actual human had the bad luck to create an account during a spambot's run. Set the reason to "Other" and add a note in the one-line box saying to contact you by email if there's a real person connected to the account.
Putting a notice on all pages
Edit MediaWiki:Sitenotice to display the text you want an all pages.
Remove the notice by blanking the same page.
- The page where we link pages that don't need to be linked to, so that they don't show up on the Orphaned Pages list: Pages we don't need to link from other pages