Good question.  On OS X it seems the size of a directory is typically a multiple of 102 bytes (often 102 or 306).  I ran my script again with &quot;find &#x2F; -type f&quot; to select only regular files, and it showed file sizes ending in 2 being just slightly more common than 0.  Odd sizes are still less common than even ones, though, so the overall conclusion is unchanged regardless of whether you consider checksumming of directory entries to be a valid application.