#include <Editions.h>

typedef struct FormatIOParamBlock {Size Offset Description

long ioRefNum; 4 0 reference number

FormatType format; 4 4 edition format type

long formatIndex; 4 8 opener-specific enumeration

of formats

unsigned long offset; 4 12 offset into format

Ptr buffPtr; 4 16 data starts here

unsigned long buffLen; 4 20 length of data