Example with mandatory variables not filled in

extra:                        # Extra
  dyn_a:                      # dyn_{{ identifier }}
    var: example

Example with all variables modifiable

rougail:                      # Rougail
  general:                    # Général
    varname:                  # No change
      - a
extra:                        # Extra
  var:                        # A variable
    - a
  dyn_a:                      # dyn_{{ identifier }}
    var: example