Proper syntax for optional header parameter for text/csv mimetype?

Question

According to RFC 4180:

...the presence or absence of the header line should be indicated via the optional \"header\" parameter of this MIME type...

Answer 1

The "header" parameter indicates the presence or absence of the header line. Valid values are "present" or "absent".

So if you use that parameter, the full MIME type would be text/csv; header=present or text/csv; header=absent.