FILE_ATTRIBUTE_UNPINNED

GetFileAttributes

 The other day I encountered an assert in some external library code. The code asserted that the high DWORD bits of the file attribute (from GetFileAttributes) should be zero. The file attribute value was 0x00100020. 

 It turned out that the high part comes from a file attribute defined in 'winnt.h':

#define FILE_ATTRIBUTE_UNPINNED             0x00100000

  This file attribute is not described in MSDN (yet). It seems to be related to 'OneDrive'.