Adding Notes to a task
Step 1. Open up the Tasks Details screen for the task you want to add a note to and click on the "Add Note" button at the bottom of the screen
Step 2. Add whatever note you want to the task. Notes are visible to everyone that looks at the task.
Step 3. Scroll down to the 'Activity' section on the 'Task details' screen to see your newly added note.
A full history of updates made to a task, includes notes added can be viewed in the Activity section. The most recent updates will appear at the top.