Example with all variables modifiable

rougail:                      # Rougail
  leader:                     # A leadership
    - leader: value1          # A leader
      follower1: val11        # A follower
      follower2: val21        # An other follower
    - leader: value2          # A leader
      follower1: val11        # A follower
      follower2: val21        # An other follower
  calculate: value2           # A calculated variable