. . . . . . "It must not be used if the format of field n is A, L, or X. For fields with all other data types, the value field shall contain a floating-point number representing the coefficient of the linear term in Eq. (7), which is used to compute the true physical value of the field, or, in the case of the complex data types C and M, of the real part of the field, with the imaginary part of the scaling fact" .