Applications may need indicators specific to their own purposes. Such indicators can be placed into the Navi pane, if it is available, or into some part of the main pane. However, using the main pane this way may require the use of a specific main pane layout. Notice also that the icons present in many list item layouts can be utilized as indicators.
The API to use for indicators is the Indicators API. For the navi pane, use the Navigation pane API. For more information, see Symbian C++ API specifications.