When you add a control to a window, you can specify some help text which appears as a tooltip when the mouse pointer is held over the control.
When writing text for context-sensitive help, answer the questions "What is this?" and "Why would I want to use it?". Indicate the action associated with the item, for example, "Identifies the user who raised the incident". Try to avoid lengthy explanations. If more detailed information is required, consider renaming the control to make it easier to know what information is required, or use static text. For more information about adding static text, see Adding labels to a window.
Avoid creating context-sensitive help for parts of the interface that do not need further explanation, such as group boxes, labels for controls, or static descriptive text fields.