This sentence means in other words: (The text has been) valdiated or edited for the last time by %s. %s is the name of a user that will be dynamically replaced when building the page.\r
maccum, "%s" is a special tag that will be replaced by a username. It's not a precetage value. I don't know if the translation is correct but maybe you maybe wat to correct it now that you know this. And it's maybe the same thing for this one. Thanks ^_^