Syntax
=====

.. code-block:: text

    LISS_SPECTRE (
        ◆ SPECTRE = _F (
             ◆/TABLE = table,
               /NAPPE = tablecloth,
             ◇ ELARG = float,
             # If: exists (" NAPPE ")
                 ◆ DIRECTION =/"X",
                               /"Y",
                               /"Z",
                               /"H",
                 ◆ NOM = text,
                 ◇ BATIMENT = text,
                 ◇ COMMENTAIRE = text,
          ),
        ◆ OPTION =/"VERIFICATION ",
                   /"CONCEPTION ",
        ◇ FREQ_MIN = float,
        ◇ FREQ_MAX = float,
        ◇ NB_FREQ_LISS = int (default: 10),
        ◇ ZPA = float,
        ◇ BORNE_X = float,
        ◇ BORNE_Y = float,
        ◇ ECHELLE_X =/"LIN" (by default),
                      /"LOG ",
        ◇ ECHELLE_Y =/"LIN" (by default),
                      /"LOG ",
        ◇ LEGENDE_X = text,
        ◇ LEGENDE_Y = text,
    )
    
    ◆: mandatory
    ◇: optional
    : present by default
    &: together
    /: only one among
    |: several possible choices