.IP CURLFORM_CONTENTSLENGTH
followed by a long giving the length of the contents. Note that for
\fICURLFORM_STREAM\fP contents, this option is mandatory.
+
+If you pass a 0 (zero) for this option, libcurl will instead do a strlen() on
+the contents to figure out the size. If you really want to send a zero byte
+content then you must make sure strlen() on the data pointer returns zero.
.IP CURLFORM_FILECONTENT
followed by a filename, causes that file to be read and its contents used
as data in this part. This part does \fInot\fP automatically become a file