The last processing action taken on your case

Application Type: I485 , APPLICATION TO REGISTER PERMANENT RESIDENCE OR TO ADJUST STATUS

Current Status: REQUEST FOR INITIAL EVIDENCE SENT, CASE PLACED ON HOLD

On July 7, 2009, we mailed a notice requesting initial evidence in this case. Please follow the instructions on the notice to submit the evidence requested. Meanwhile, processing of this case is on hold until we either receive the evidence or the opportunity to submit it expires. Once you submit the evidence requested and a decision is made, you will be notified by mail. If you move while this case is pending, please use our Change of Address online tool to update your mailing address.

무슨 말인지 부탁드려요.. 이게 REF 멜 보낸다는 말인가요
아님 인터뷰 한다는 말인가요?
인터뷰한다면 무슨 통보쪽지라도 보내나요?
궁금합니다.
참고로 전 2005년 8월 PD 입니다. 무슨말인지 부탁드립니다.