docs: def _create_skeleton_3(pc, l, num_section):
      """
      Bottom level: {"measurement": [], "model": [{summary, distributions, ensemble}]}
      Fill in measurement and model tables with N number of EMPTY meas, summary, ensemble, and distributions.
      :param str pc: Paleo or Chron "mode"
      :param list l:
      :param dict num_section:
      :return dict:
      """
      logger_excel.info("enter create_skeleton_inner_2")
  
      # Table Template: Model
      template_model = {"summaryTable": {}, "ensembleTable": {}, "distributionTable": []}
  
      # Build string appropriate for paleo/chron mode
      pc_meas = "{}MeasurementTable".format(pc)
      pc_mod = "{}Model".format(pc)
  
      # Loop for each table count
      for idx1, table in num_section.items():
          try:
              # Create N number of empty measurement lists
              l[idx1 - 1][pc_meas] = [None] * num_section[idx1]["ct_meas"]
  
              # Create N number of empty model table lists
              l[idx1 - 1][pc_mod] = [copy.deepcopy(template_model)] * num_section[idx1]["ct_model"]
  
              # Create N number of empty model tables at list index
              #
              for idx2, nums in table["ct_in_model"].items():
                  dists = []
                  try:
                      # Create N number of empty distributions at list index
                      [dists.append({}) for i in range(0, nums["ct_dist"])]
                  except IndexError as e:
                      logger_excel.debug("excel: create_metadata_skeleton: paleo tables messed up, {}".format(e))
  
                  # Model template complete, insert it at list index
                  l[idx1 - 1][pc_mod][idx2-1] = {"summaryTable": {}, "ensembleTable": {}, "distributionTable": dists}
          except IndexError as e:
              logger_excel.warn("create_skeleton_inner_tables: IndexError: {}".format(e))
          except KeyError as e:
              logger_excel.warn("create_skeleton_inner_tables: KeyError: {}".format(e))
      return l