(RFC 5537 published November 2009, subtype last updated November 2009)

MIME type name:           application

MIME subtype name:        news-groupinfo

Required parameters:      none

Optional parameters:      charset, which MUST be a charset
                          registered for use with MIME text types.
                          It has the same syntax as the parameter
                          defined for text/plain [RFC2046].
                          Specifies the charset of the body part.
                          If not given, the charset defaults to
                          US-ASCII [ASCII].

Encoding considerations:  7bit or 8bit encoding MUST be used to
                          maintain compatibility.

Security considerations:  None.

Interoperability considerations:
                          Disposition should by default be inline.

Applications that use this media type:
                          Control message issuers, relaying
                          agents, serving agents.

Published specification:  RFC 5537

Intended usage:           COMMON

Change controller:        IETF

The content of the application/news-groupinfo body part is defined
as:

   groupinfo-body      = [ newsgroups-tag CRLF ]
                            newsgroups-line CRLF
   newsgroups-tag      = %x46.6F.72 SP %x79.6F.75.72 SP
                            %x6E.65.77.73.67.72.6F.75.70.73 SP
                            %x66.69.6C.65.3A
                            ; case sensitive
                            ; "For your newsgroups file:"
   newsgroups-line     = newsgroup-name
                            [ 1*HTAB newsgroup-description ]
                            [ *WSP moderation-flag ]
   newsgroup-description
                       = eightbit-utext *( *WSP eightbit-utext )
   moderation-flag     = SP "(" %x4D.6F.64.65.72.61.74.65.64 ")"

                            ; SPACE + case sensitive "(Moderated)"
   eightbit-utext      = VCHAR / %d127-255

This unusual format is backward-compatible with the scanning of the
body of newgroup control messages for descriptions done by Netnews
implementations that predate this specification.  Although optional,
the <newsgroups-tag> SHOULD be included for backward compatibility.

The <newsgroup-description> MUST NOT contain any occurrence of the
string "(Moderated)" within it.  Moderated newsgroups MUST be marked
by appending the case-sensitive text " (Moderated)" at the end.

While a charset parameter is defined for this media type, most
existing software does not understand MIME header fields or correctly
handle descriptions in a variety of charsets.  Using a charset of US-
ASCII where possible is therefore RECOMMENDED; if not possible, UTF-8
[RFC3629] SHOULD be used.  Regardless of the charset used, the
constraints of the above grammar MUST be met and the <newsgroup-name>
MUST be represented in that charset using the same octets as would be
used with a charset of US-ASCII.