When the device reaches the specified points during playback, the MM_MCICUEPOINT message is returned to the application using the window handle specified in the hwndCallback field. When setting a cue point on, the hwndCallback field must contain a valid window handle. An error is returned if a NULL or invalid window handle is specified in pParam2. Each cue point can be directed to a different window handle.

Only one cue point can be set at any given location in the media.

Cue points can only be set when a device element is loaded, and are reset when a new device element is loaded.

Cue points are persistent, that is they remain set after they are encountered. A cue point is only considered to have been encountered when the device passes the cue point location during playback or recording, not during seek operations.

If the length of a file cannot be determined, MCIERR_SUCCESS might be returned even though the specified point is out of range.

Devices that do not perform their own event detection might have less accurate cue points.