# Using the function reference

A typical function description includes:

Prototype | The prototype is shown followed by a listing of the function's arguments. Data types include: WORD (16-bit unsigned) DWORD (32-bit unsigned) INT16 (16-bit signed) INT32 (32-bit signed) BYTE (8-bit unsigned) If a function argument is a data structure, the complete data structure is defined. Refer to CDI service parameters for a description of all data structures and parameters.
Return values | The return value for a function is either SUCCESS or an error code. For asynchronous functions, a return value of SUCCESS indicates the function was initiated. Subsequent events indicate the status of the operation. Refer to the CDI service errors for a list of errors returned by CDI service functions.
Events | Asynchronous functions list DONE events when the function is complete. Additional information such as reason codes and return values may be provided in the value field of the event. Synchronous functions do not generate events. Refer to the CDI service events for information about CDI service events and reason codes.
Example | Example functions that start with Demo are excerpts taken from demonstration function libraries shipped with the product. Example functions that start with my are excerpts taken from sample application programs shipped with the product. The notation /* ... */ indicates additional code that is not shown.

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