# Using the MMFI library function reference

The function reference describes each MMFI function and displays its prototype, return values, and associated events (if any). It provides additional details, when necessary, and also provides a code sample for the function.

Prototype | The prototype is followed by a listing of the function's arguments. Each of the MMFI library functions has the DWORD (16-bit unsigned) data type. If a function uses a structure, the structure is listed as an argument.
Return values | A return value of SUCCESS (0) indicates the function was initiated; subsequent events indicate the status of the operation. Other possible return values are listed in the description of each individual call.
Events | MMFI library events are returned in the application's event buffer. Additional information such as reason codes and return values may be provided in the value field of the event.
Example | Example functions are taken from sample application programs shipped with the product. The notation /* ... */ indicates additional code that is not shown.