Note
Within the Note, you're free to expound upon your ideas extensively. It supports the use of ordered or unordered lists for itemized explanation, and text can be emboldened, italicized, or underlined for emphasis.
Notes are rich-text annotations for topics. They’re a great solution when you wish to provide detailed elaboration without cluttering the overall simplicity of your mind map.
Add Note
Select a topic and add note by choosing Notes from the Insert button in the toolbar.
With the topic selected, click Notes in the Insert in the top menu bar to add it.

After selecting a topic, use a combination of shortcuts to add it:
Windows:Ctrl+Shift+N
Mac:⇧+⌘+N
Delete Note
Just delete the contents of the notes box directly or Right Click > Delete.