What does this mean? What kind of "Document" they sent me?
Application Type: I485, APPLICATION TO REGISTER PERMANENT RESIDENCE OR TO ADJUST STATUS
Current Status: Document mailed to applicant.
On March 18, 2008 we mailed the document to the address we have on file. You should receive the new document within 30 days. If you do not, or if you move before you get it, call customer service.