Codebooks required for NC Electrical Exams: Ltd, Unlimited and Intermediate. Effective 2-2021, the NC Board voted to allow candidates to bring their own reference materials for use during examinations. The examinations are OPEN BOOK. The references listed are the ONLY references allowed in the examination center. References shall be softbound, spiral, or hardbound. Loose leaf references are not allowed. Candidates are responsible for bringing their own references to the examination center Acceptable Tabs: Redi-Tag Self-Stick Permanent Adhesive Index Tabs Reference Materials to bring to testing center: The National Electrical Code, current edition. National Fire Alarm Code, current edition (Limited, Intermediate, Unlimited, SP -SFD and SP -FA/LV).