The Materials Reference System or MRS is a collection of contract administration materials assembled by the NALC Headquarters’ Contract Administration Unit. It has been designed to assist all NALC representatives who enforce and administer the National Agreement. The MRS should be used as a supplement to the Joint Contract Administration Manual (JCAM) which is authoritative and controlling in the case of any ambiguities or contradictions.
The MRS contains summaries and, in some cases, the full text of many important national-level materials, including settlements of Step 4 Settlement, grievances, national-level Pre-arbitration settlements, Memorandums, USPS policy statements, NALC publications and more. The MRS also contains cross-references to significant national-level arbitration awards.

Materials Reference System (MRS) forms can be found here