Home Glossary CSI MasterFormat Glossary CSI MasterFormat By Deviation Check Editorial Team. Short answer The Construction Specifications Institute standard that organizes construction specifications into numbered divisions and sections. It is the common filing system for North American specs and the backbone of how submittals are tracked. Related terms Spec sectionSubmittal log Browse the full glossary, the CSI division guides, or learn how submittal review works. Then run a review. View this page as Markdown for LLMs and note-taking.