Content-Type: text/plain Content-Disposition: inline Content-Transfer-Encoding: binary MIME-Version: 1.0 X-Mailer: MIME-tools 5.411 (Entity 5.404) RT-Send-CC: X-RT-Original-Encoding: iso-8859-1 Content-Length: 310 Actually, why would an application ever be using this value? This #define is the value of the old data structure size, not the new size. Programmers should never be setting the size to that value. Programmers should always be setting the size to sizeof(struct ...) I am just going to correct the definition.