for reference purposes you can find a list of the macros involved in declared startup and shutdown functions in おもて 313 these are not used in our basic example yet but will be demonstrated later on you should make use of these macros to declare your startup and shutdown functions as these require special arguments to be passed init _ func _ args and shutdown _ func _ args which are automatically included into the function declaration when using the predefined macros if you declare your functions manually and the php developers decide that a change in the argument list is necessary youll have to change your module sources to remain compatible 