FN means that this routine will return a result. If you are building a routine for a procedure, you eliminate this word.
Name is case sensitive.
It is one of the few things in FB that must exactly match Apple's upper and lower case designations. If you don't get this right, the PPC version of your application will crash when the toolbox is used. 68K code is taken directly from the headers supplied by Apple. It does not return a value. This first example shows a very simple conversion from a C headers file.