Apple Workgroup Server 6150/66 - Manual (Page 48)

Make sure that the tab on the side of the card assembly slides into the slot on
the side of the case, as shown.
10 Attach the thumbscrews to the access port on the server’s back panel.
Position the bracket against the access port while inserting and tightening
the thumbscrews.
Adapter card assembly
Thumbscrews
Adapter card assembly
Slot in computer case
Tab
32 Chapter 3 / Expanding Your Server and Connecting Other Equipment