Per suggestion of The Evil IP address: http://translatewiki.net/wiki/Thread:Support/userinvalidcssjstitle
'userjspreview' => "'''Remember that you are only testing/previewing your user JavaScript.'''
'''It has not yet been saved!'''",
'userinvalidcssjstitle' => "'''Warning:''' There is no skin \"\$1\".
-Remember that custom .css and .js pages use a lowercase title, e.g. {{ns:user}}:Foo/monobook.css as opposed to {{ns:user}}:Foo/Monobook.css.",
+Custom .css and .js pages use a lowercase title, e.g. {{ns:user}}:Foo/vector.css as opposed to {{ns:user}}:Foo/Vector.css.",
'updated' => '(Updated)',
'note' => "'''Note:'''",
'previewnote' => "'''Remember that this is only a preview.'''