Five special C functions take care for internal matters within a PHP extension: %MINIT%, %MSHUTDOWN%, %RINIT%, %RSHUTDOWN% and %MINFO%. %MINIT% and %MSHUTDOWN% are called on initialization and shutdown of an extension within PHP, these are called exactly once. Any initialization and cleanup you need to do globaly should be added here. %RINIT% and %RSHUTDOWN% are called on the beginning and end of each request handled by PHP. Depending on the server api these may be called just once or many times. Any per request initialization and cleanup needed should be added here. %MINFO% is called to produce the extensions output for %phpinfo()% whenever this function is called. All these functions are generated for you. Only if you have to add special code you need to add %<function>% tags for them. Usually you will only add code for %MINIT% and %MSHUTDOWN%. Internal functions are specified by setting the %role% attribute to %"internal"%.