.ONETOC2 File Extension
File TypeMicrosoft OneNote Table of Contents File
This file is saved in a binary format, which requires a specific program to read its contents.
What is an ONETOC2 file?
Index file created by Microsoft OneNote, a program used for personal journaling and note taking; stores information about the ordering of different note-taking sections; used for organizing the collection of notes in the notebook.
If the ONETOC2 file is deleted, OneNote will display the notebook sections in alphabetical order, which the user can manually reorder.