Formal grading systems for documentation of scientific evidence for policies and procedures

Many organizations have formal grading systems for documentation of scientific evidence for policies and procedures. Share the practices of your organization (or one that you are familiar with). To do this, reflect on your organization and answer the following questions: Does your institution have an evidence-based grading system used for writing procedures? If so, what is it, and how well is it utilized either on your unit or in the institution? Is there a grading system used predominantly by your profession or specialty within your profession?