23 Patron Status Request language 3-char, fixed-length required field transaction date 18-char, fixed-length required field: YYYYMMDDZZZZHHMMSS institution id AO variable-length required field patron identifier AA variable-length required field terminal password AC variable-length required field patron password AD variable-length required field 09 Checkin no block 1-char, fixed-length required field: Y or N. transaction date 18-char, fixed-length required field: YYYYMMDDZZZZHHMMSS return date 18-char, fixed-length required field: YYYYMMDDZZZZHHMMSS current location AP variable-length required field