Plain Text is a text entry field that does not contain any special word processing tools.  It is best used for simple text or for devices or browsers that do not support Rich Text entries. Plain text entries can, however, support markdown for some simple formatting.

To access Plain text, choose Plain Text in the: “Add Entry” toolbar, or under “+ New”.

This will open up the “Plain Text” window.

Enter your text and click “Save to page”.

The Plain Text entry can support the minimal markup language called Markdown. To turn off markdown for plain text entries go to the triple dot menu on the top right and select “Notebook Settings”.

Note: The mobile app does not support markdown.

Note: Only Owners and Administrators of the notebook can turn this functionality on.

You can also turn the formatting off for a specific entry by typing  #!IGNORE_MARKDOWN at the beginning of the plain text entry. #!IGNORE_MARKDOWN must be the very first string of text and it will not be displayed after the entry is saved.

 
Some examples of markdown formatting supported by the plain text entry are shown below. You can also nest formatting as seen in the example below.

Note: While the entry is in edit mode the text will appear with the syntax. After clicking save to page the entry will show with formatting.

Plain Text Entry with Markdown in Edit Mode

Plain Text Entry with Markdown in View Mode

Plain Text Entry with Markdown in Edit & View Mode

To swap to view mode, click the keyboard icon that is located in the red square in the top right corner of the plain text entry. 

For more information on Markdown see the article linked HERE