WM_ASKCBFORMATNAME  1MMR03T 

The WM_ASKCBFORMATNAME message is sent to the clipboard owner by a clipboard viewer window to request the name of a CF_OWNERDISPLAY clipboard format.

WM_ASKCBFORMATNAME

cchName = (DWORD) wParam            // size of buffer

lpszFormatName = (LPTSTR) lParam    // buffer to receive format name

Parameters

cchName

Value of wParam. Specifies the size, in characters, of the buffer pointed to by the lpszFormatName parameter.

lpszFormatName

Value of lParam. Points to the buffer that is to receive the clipboard format name.

Return Values

If an application processes this message, it should return zero.

Remarks

In response to this message, the clipboard owner should copy the name of the owner-display format to the specified buffer, not exceeding the buffer size specified by the cchName parameter.

A clipboard viewer window sends this message to the clipboard owner to determine the name of the CF_OWNERDISPLAY format   for example, to initialize a menu listing available formats.