/sys$common/syshlp/helplib.hlb RTL Routines, LIB$, LIB$MOVC3, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 word-integer-length

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

    Number of bytes to be moved from source to destination by
    LIB$MOVC3. The word-integer-length argument is the address of
    an unsigned word that contains this number of bytes. The maximum
    transfer is 65,535 bytes.

 source

    OpenVMS usage:unspecified
    type:         unspecified
    access:       read only
    mechanism:    by reference

    Item to be moved. The source argument is the address of this
    item.

 destination

    OpenVMS usage:unspecified
    type:         unspecified
    access:       write only
    mechanism:    by reference

    Item into which source will be moved. The destination argument is
    the address of this item.