Display comments of a task

From the book inbox, click on Comments : 

Comments are displayed on the right side of the page : 

Add a comment

Once comments are displayed on the page, type a comment in the inbox :

Then click to send : 

Modify a comment

When you fly over your comment, a pencil icon appears : 

Click on the icon and directly modify your comment : 

Click on the pencil icon to validate your modifications.

Delete a comment

When you fly over your comment, a trash bin icon appears :

Click on the icon to definitively delete your comment.

Note : Caution, this action is definitive.