The Notes field allows you to enter comments or additional explanation for the Task. When a Note is included in a Task, the Notes indicator, a red triangle, appears in the upper right corner of the Task shape.
The contents of the Notes field are visible in three ways:
By selecting Define Task Details… from the right-click menu of the Task shape
By hovering over the Notes indicator when using Visio to view a TaskMap
By hovering over the Notes indicator when using a web browser to view a TaskMap. (NOTE: this option is only available for TaskMap web pages created with Visio 2003 or later.)