2018 Document 6209 is a reference guide which contains ADP and IDRS data relative to various components of the IRS. It is updated annually. Table of Contents PDFSection 1, Glossary PDFSection 2, Tax Returns and Forms PDFSection 3, Tax Return Information PDFSection 4, Document Locator Number PDFSection 5, Debtor Master File PDFSection 6, Initiating and Monitoring Refund Check Tracing Action PDFSection 7, Automated Non-Master File PDFSection 8A, Master File Codes - Transaction, MF and IDRS Collection Status, Freeze and IDRS Status 48, Restrictive and Filing Requirements PDFSection 8B, Master File Codes - Unpostable and Resequence PDFSection 8C, Master File Codes - Source, Reason, Hold, Priority, Item Adjustment & Credit Reference, NMF Abstract, Underreporter, Process, No Merge Reason, EP PDFSection 9, Notices and Notice Codes PDFSection 10, Penalty and Interest Provisions PDFSection 11, Collection PDFSection 12, Examination PDFSection 13, Appeals and TE/GE PDFSection 14, Integrated Data Retrieval System (IDRS) PDFSection 15, Other Systems CADE, CADE 2, SCRIPTS, CFOL and FTD PDFSection 16, Julian Date, Cycle and Notice Calendars PDFAppendix PDF