Help talk:System message

how to "Create new messages"
Front page here says:
 * "... Extensions can (and should) define system messages for any text displayed in the user interface. This assists in the localization of those messages. For an example of how to do this, please see Manual:Special pages..."

... but I can't figure out how to create a new message (as might support Extension:PageNotice, for instance) - are there any examples here on how to create such new mediawiki system messages? thanks peblusto 14:34, 2 January 2008 (UTC)