When doing an HTML Export (Table with Columns and Bullet List), it is possible to specify HTML tags that should be excluded from the HTML export, i.e. {private}

 

To mark sections of text, first select the text you wish to "hide" from the HTML export, then use the Doc pane function  Menu > Edit > Enclose text with (Ctrl + Shift + T)

 

Alternately,  you may manually enter the tags, for example {private} before the text block, and {/private} after the text block

 

 

 

You will be prompted for a tag:

 

 

The selected text will then be enclosed with this tag (yellow highlight was added)

 

 

When doing an HTML Export, enter the HTML tags to hide:

 

 

 

Notes: