An information icon is specified with the ``-I'' flag, and should be used for outputing non-critical information to the user, or asking them a simple question. It is also the default icon, and will be used if you do not specify another one. Example:
opie-sh -m -I
A warning icon is specified with the ``-w'' flag, and should be used for problems that the user should know about, but that will not necessarily cause the program to stop working. For example, if the program cannot find a configureation file, you might pop up a warning, notifying the user that the default configuration will be used. This is also useful for asking the user if they want to continue doing something that might damage the system (editing rc scripts, for instance). Example:
opie-sh -m -w
An error icon is specified with the ``-e'' flag, and should be used for problems that will cause the program to stop running, or otherwise do the wrong thing. It should be used sparingly, as it signifies that something is seriously wrong. Example:
opie-sh -m -e