Thanks -- there are still some templates and locale keys that refer to concepts that existed in OJS 2.x but don't (yet) in OJS 3.x. We're working on these gradually -- and some we will probably not opt to implement -- so in the interests of not removing translations that will later become useful, we've left some of these in the locale files. If you like, leave those untranslated and they'll remain in the translator plugin as unfinished until we decide whether to implement or remove from the English files. Pardon our mess as we continue to push forward on OJS 3.x!
Public Knowledge Project Team