Thank you for your response. I couldn't get the Fx button to work - it seemed to populate incorrect syntax for the rest URL. The odata site was very helpful. I was able to create this:
webapp/departments/it/hd/_vti_bin/listdata.svc/ServiceRequests?$top=5&$orderby=Id desc&$filter=StatusValue eq 'Completed' to accomplish what I needed.
Thank you for your help!