Thread:Support/How to move a MediWiki message to another source file?

I want to fix bug 20781 - Move 'mainpagetext' message to installer's .i18n file once it exists - and am facing this question for which I could not find an answer in a help page: (-: Being the lazybone I am, I'd of course prefer number one :-) Where should the advise how to do message moves and renames be kept? --Purodha Blissenbach
 * 1) do we just move the english source message and leave it to  and translators to add translations, usually with a one-click copy from translation memory, giving the opportunity to verify or amend old translations, and leave it to message export to get rid of the now unused translations of the original message, or
 * 2) should we move each translation as well?