DataBrowserCompareProcPtr

DataBrowserCompareProcPtr
Header:	ControlDefinitions.h		Carbon status:	Under Evaluation

typedef Boolean(* DataBrowserCompareProcPtr) (
    ControlRef browser, 
    DataBrowserItemID itemOne, 
    DataBrowserItemID itemTwo, 
    DataBrowserPropertyID sortProperty
);

You would declare your function like this if you were to name it MyDataBrowserCompareCallback:

Boolean MyDataBrowserCompareCallback (
    ControlRef browser, 
    DataBrowserItemID itemOne, 
    DataBrowserItemID itemTwo, 
    DataBrowserPropertyID sortProperty
);