At the beginning of the property set stream is a header. It consists of a byte-order indicator, a format version, the originating operating system version, the CLSID, and a reserved field.
The following pseudo-structure illustrates the header:
typedef struct tagPROPERTYSETHEADER
{
// Header
WORD wByteOrder ; // Always 0xFFFE
WORD wFormat ; // Always 0
DWORD dwOSVer ; // System version
CLSID clsID ; // Application CLSID
DWORD reserved ; // Should be 1
} PROPERTYSETHEADER;