Cursors of different shapes should be used for different purposes.
Additional Information:
The shape of a cursor should reflect the state of the system or processing mode. A specific cursor should be uniquely assigned to a specific purpose to provide state or mode information to the user. A straight line cursor might be used as the placeholder cursor to indicate entry position in a word processing task, an arrow might be used as a pointing cursor to indicate screen structures, and an X-shaped pointing cursor might be used when the user cannot interact with the system. Within this general framework, the number of cursor shapes used should be kept to a minimum.