MediaWiki:Translate-checks-pagename/en
Fragment of a discussion from Support/LiquidThreads
What it means is that the namespace of the message (in this case "Help") should stay the same in translations. It was translated as "Nápověda:Odkazy" when it should be "Help:Odkazy". (Ideally, I guess it should be {{ns:Help}}:Okazy, though.) I do agree that the message needs better wording to make this clear though, but I don't have any good suggestions on how to improve it at the moment.