Data category name and type changes

hmmm... ok, thinking about country list, indicator name, source changes...
what if an indicator changes source? => new node version with a date on it. never edit the original.
i will use the source data from them now. without checking it against any "official" country code repositories
when changes happen, i guess we continue the good rule: only create new versions / new nodes for changed / new countries. never delete!
i will key on indicator code, country code
and i will create Node ID obviously for the indicator-category and indicator-source. those can be versioned, or new can be created