code: function checkAmbiguous(k) {
      let i = k.indexOf('~');
      if (i !== -1) {
          let stem = k.substring(0, i);
          ambiguous[stem] = true;
          return true;
      }
      return false;
  }
docs: Some keys contain a disambiguation mark:  "Eko~ca" vs "Eko~gr" If so, we save these in an `ambiguous` object for later use