Situations often occur where a certain function cannot be used. In these cases, the corresponding items in the Options menu must either be hidden, or there must be an error message given when the user tries to access a function that cannot be accomplished. The Symbian user interface does not use dimming of menu items.
This is a trade-off issue: removing unnecessary options makes the Options menus shorter, but at the same time it changes the menu from situation to situation, preventing users from learning the function locations. It may even cause frustration if the users expect some function to be found in the menu, but it is sometimes not there.
In case the user has no reason to search for a certain function in the given situation, it should be hidden. As an extreme example, the Delete option is not needed when there are no items to be deleted.
If the user searches for a function, even though it cannot be used in the current situation, it is often better to display the option and give an appropriate message if the user tries to access that function.
An example of this is Digital Rights Management (DRM) protected files: for example, sending commands shall be visible in the user interface although sending such a file would not be allowed. Appropriate DRM-specific notifications are displayed if the user attempts to select one of the options that the user is not allowed to perform on DRM-protected media objects. This is to facilitate end-user's learning of the DRM concept.