library_index
    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Library control index returned by the LBR$INI_CONTROL routine.
    The library_index argument is the address of the longword that
    contains the index.
 index_number
    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Library index number. The index_number argument is the address of
    a longword containing the number of the index you want to search.
 rfa_to_find
    OpenVMS usage:vector_longword_unsigned
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference
    Record file address (RFA) of the module whose keys you are
    searching for. The rfa_to_find argument is the address of
    a 2-longword array containing the RFA (returned earlier by
    LBR$LOOKUP_KEY or LBR$PUT_RECORD) of the module header.
 routine_name
    OpenVMS usage:procedure
    type:         procedure value
    access:       read only
    mechanism:    by reference
    Name of a user-supplied routine to process the keys. The routine_
    name argument is the address of the procedure value of a user-
    supplied routine to call for each key entry containing the RFA
    (in other words, for each key that points to the same module
    header).
    This user-supplied routine cannot contain any calls to
    LBR$DELETE_KEY or LBR$INSERT_KEY.
 flags
    OpenVMS usage:mask_longword
    type:         longword unsigned
    access:       read only
    mechanism:    by reference
    If present and nonzero, the flags argument specifies the type, or
    all types, of the key provided. The flag bits are as follows:
    Flag Bits               Description
    LBR$M_SYM_WEAK = 0x1    UNIX-style weak symbol attribute
    LBR$M_SYM_GROUP = 0x2   Group symbol attribute
    LBR$M_SYM_ALL =         All symbols
    0x80000000
    The user routine is provided the symbol's type through an
    additional third parameter.