(i.e.: HTML and plain text), this header must be set to "multipart/alternative".
In all cases the value must be of the form "multipart/*" to respect the
document structure and may not include the "boundary=" parameter.
-.P
+
Other specific headers that do not have a libcurl default value but are
strongly desired by mail delivery and user agents should also be included.
These are "From:", "To:", "Date:" and "Subject:" among others and their
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if the
enabled value is not supported.
.SH "SEE ALSO"
-.BN CURLOPT_CRLF (3),
-.BN CURLOPT_TRANSFERTEXT (3),
+.BR CURLOPT_CRLF (3),
+.BR CURLOPT_TRANSFERTEXT (3),
.BR CURLOPT_HTTPPROXYTUNNEL (3),
.BR CURLOPT_PROXY (3)