You can save notes that belong to the project. They will be saved in the .idea-folder.
So if you don't track your .idea-folder with git, the notes are also not tracked.
So you can call it "private notes".
IntelliJ - Plugin IntelliJ (and all intellj based IDEs) from jetbrains can use plugins to expand the range of functions. This is a Plugin for all intellj-based IDEs.
What can I do with this ?
With this plugin, you can save some notes to your project on an very easy way. It's txt-format.The notes will be stored in .idea folder - so normally they will not be tracked by a version system (like git), if you exclude your .idea -folder from git.
If you **want** to be your notes to be tracked by git, you can add this line into your .gitignore file: !.idea/.curNotes.txt
If you prefere MardDown-Format - please have a look at my CurNotesMD - this plugin will save Notes in markdown-Format
Jörg Wrase www.cusp.de