VMS Help RTL Routines, LIB$, LIB$RADIX_POINT, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 radix-point-string

    OpenVMS usage:char_string
    type:         character string
    access:       write only
    mechanism:    by descriptor

    Radix point string. The radix-point-string argument is the
    address of a descriptor pointing to this radix point string.

 resultant-length

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference

    The number of characters written into radix-point-string, not
    counting padding in the case of a fixed-length string. The
    resultant-length argument is the address of an unsigned word
    that contains this number.

    If the radix-point-string argument is the address of a fixed-
    length string descriptor, there may not be enough characters
    in the fixed-length string to contain the whole radix point
    string, and the radix point string is truncated. If the radix
    point string is truncated to the size specified in a fixed-
    length string descriptor, resultant-length is set to this size.
    Therefore, resultant-length can always be used by the calling
    program to access a valid substring of radix-point-string.