2. Syntax

interspectrum = LIRE_INTE_SPEC (
    ◆ UNITE = unit,
    ◇ FORMAT_C =/"REEL_IMAG ",
                 /"MODULE_PHASE" (by default),
    ◇ FORMAT =/"ASTER" (by default),
               /"IDEAS ",
    ◇ NOM_PARA =/"DX",
                 /"DY",
                 /"DZ",
                 /"DRX ",
                 /"DRY ",
                 /"DRZ ",
                 /"TEMP ",
                 /"INST ",
                 /"X",
                 /"Y",
                 /"Z",
                 /"EPSI ",
                 /"FREQ" (by default),
                 /"PULS ",
                 /"AMOR ",
                 /"ABSC ",
    ◇ NOM_RESU = text (default: "DSP "),
    ◇ INTERPOL =/"LIN ",
                 /"LOG ",
    ◇ PROL_DROITE =/"CONSTANT ",
                    /"LINEAIRE ",
                    /"EXCLU ",
    ◇ PROL_GAUCHE =/"CONSTANT ",
                    /"LINEAIRE ",
                    /"EXCLU ",
    ◇ TITRE = text,
    ◇ INFO =/1 (by default),
             /2,
)

◆: mandatory
◇: optional
: present by default
&: together
/: only one among
|: several possible choices