VMS Help RTL Routines, MTH$, MTH$xSINH, Argument  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 floating-point-input-value

    OpenVMS usage:floating_point
    type:         F_floating, D_floating, G_floating
    access:       read only
    mechanism:    by reference

    The input value. The floating-point-input-value argument is
    the address of a floating-point number that is this value. For
    MTH$SINH, floating-point-input-value specifies an F-floating
    number. For MTH$DSINH, floating-point-input-value specifies a
    D-floating number. For MTH$GSINH, floating-point-input-value
    specifies a G-floating number.