The NCS$GET_CF routine extracts the named conversion function
    from the specified NCS library.

    If the calling program omits the cfname argument, an "identity"
    conversion function padded with NUL characters (hex 0) is
    provided. The identity conversion function effectively leaves
    each character unchanged by converting each character to itself.
    For example, A becomes A, B becomes B, C becomes C, and so forth.

    If the calling program omits the librar argument, NCS accesses
    the default NCS library.