Labels can now be attached to Resource Gantt charts and Order Gantt charts.
There are two types of labels: Bubble and Arrow. Standard red, blue, green, and yellow labels can be added easily from the menu or tool buttons.  You can use the mouse to adjust the position and size of labels.
Not only can you attach labels containing notes and the like to work instructions, you can also attach labels to working times to display the reason why a piece of equipment was stopped.
When you print a chart, the labels are also printed. Printed charts can be distributed to the shop floor to share notes and other supplementary information along with the schedule.

Asprova Help
  -> http://lib.asprova.com/onlinehelp/en/AS2003HELP00668330.html
  -> [GUI]->[Table Time Chart Window]-[Shared Operations]-[Label] – HelpNo.:668330