Identify localized strings that are not used in the code of the app.
Resolution: remove those strings.
Identify localized strings that are used in code but does not appear in the .strings files.
Resolution: add those strings and localize them.
Identify strings that are localized only on a subset of languages your application declare to support.
Resolution: localize those strings on the missing languages.
Identify localized strings which do not have a comment in the .strings files.
Resolution: add /* a comment */ above the definition of the localized string.