A few weeks ago, I visited the Tract Department in the Cook County Recorder of Deeds office (118 N. Clark Street, Room 120, Chicago, Illinois 60602 ) and got some help book and paging some c. 1910 documents that I wanted to view. As the clerk looked at the list, three document numbers stood out to her. One had the letters "M L" following the number. I learned that this means "mechanic's lien" and that those early records aren't available.
One of the other two numbers--six digits each--had "C" following it and the other had an "S." The clerk mentioned that they might be "corporation" documents. It seemed a bit odd--the transaction appeared to be between family members--but we book and paged them and I went across the hall to have the corresponding microfiche pulled. The clerk there told me those particular records would have to be retrieved from the warehouse, so I placed the order.
I went across the street to the Circuit Court Archives, checked the Superior Court index, and made a discovery.The document listed in the Tract Book (266999 S) was indeed the case number for a divorce granted to the two people whose names were entered in the book. I had actually made copies from that file a few weeks ago.
Looking at the tract book page again I see many things that I didn't notice before--in part because I was focusing on finding documents rather than understanding the index and in part because I should have put my glasses on the first time around. : )
|(These entries were actually in the middle of the page. I moved them up so the column headings would be visible.)|
I suspect I will find that the document number followed by a "C" is a Circuit Court case and looking back through my notes, I don't believe I've looked at that file. I'm hoping it might provide new insights into a complicated story. I also think a few of the other entries on the page might be for court documents as well and I plan to follow up.
I'm adding this image as a follow-up to the comment made by K Craine. I believe it shows the notation for probate.