The navigation usually includes five buttons and can include more. The 3902 has four, though, as the enter button in the center is missing.
In general, all station types have an up, down, left, and right arrow. This moves the cursor in the applicable screen. For example, this is used when changing the Node ID and TN in the UNIStim registration data.
Most stations have a quit button (sometimes with the image of a stop sign on it, instead of words). This allows the user to exit an active application, such as scrolling through the personal directory, without ending an active call.
Other:
The release button can also close the application (as can any soft keys that may be available at the time), but the release button will end active calls if one exists and is best avoided when closing applications during a call.
In addition, many IP stations include an enter button in the center of the navigation arrows. This can be used instead of the Select soft key, when the Enter fixed key is present.
