Private Clipboard Formats

An application can identify a private clipboard format by defining a value in the range CF_PRIVATEFIRST through CF_PRIVATELAST. An application can use a private clipboard format for an application-defined data format that does not need to be registered with the system.

Data handles associated with private clipboard formats are automatically freed by the system. Windows that use private clipboard formats can use the WM_DESTROYCLIPBOARD message to free any related resources that are no longer needed.

For more information about the WM_DESTROYCLIPBOARD message, see Clipboard Ownership.

An application can place data handles on the clipboard by defining a private format in the range CF_GDIOBJFIRST through CF_GDIOBJLAST. When using values in this range, the data handle is not a handle to a GDI object, but is a handle allocated by the GlobalAlloc function with the GMEM_MOVEABLE flag. When the clipboard is emptied the system automatically deletes the object using the GlobalFree function