(RFC 3839 published July 2004, subtype last updated July 2004. 
RFC 6381 does not contain a registration template.)

MIME media type name:              audio
MIME subtype name:                 3gpp
Required parameters:               none
Optional parameters:               none
                                    Ongoing work related to this
                                    registration may introduce new
                                    optional parameters.  One example
                                    area of effort may introduce a
                                    parameter that would allow for
                                    codecs in use within the MIME type
                                    to be asserted and determined
                                    without examination of the file.
                                    Those with interests in the area
                                    should monitor registrations for
                                    updates.
Encoding considerations:           files are binary and should be
                                    transmitted in a suitable encoding
                                    without CR/LF conversion, 7-bit
                                    stripping etc.; base64 is a suitable
                                    encoding.  Note that this MIME type
                                    is used only for files; separate
                                    types are used for real-time
                                    transfer, such as for the RTP
                                    payload format for AMR audio
                                    [RFC3267].
Security considerations:           see the security considerations
                                    section in RFC 3839
Interoperability considerations:   The 3GPP organization has defined the
                                    specification, interoperability, and
                                    conformance, and conducts regular
                                    interoperability testing.
Published specification:           3GPP 26.234, Release 5; 3GPP 26.244,
                                    Release 6 or later.  3GPP
                                    specifications are publicly
                                    accessible at the 3GPP web site,
                                    www.3gpp.org.
Applications which use this media type: Multi-media
Additional information:            The type "audio/3gpp" MAY be used for
                                    files containing audio but no visual
                                    presentation.  Files served under
                                    this type MUST NOT contain any
                                    visual material. (Note that 3GPP
                                    timed text is visually presented
                                    and is considered to be visual
                                    material).

Magic number(s):                   None.  However, the file-type box
                                    must occur first in the file, and
                                    MUST contain a 3GPP brand in its
                                    compatible brands list.
File extension(s):                 3gp and 3gpp are both declared at
                                    http://www.nist.gov/nics/; 3gp is
                                    preferred
Macintosh File Type Code(s):       '3gpp'
Person & email address to contact for further information:
                                    Nokia MIME manager, mime&nokia.com
Intended usage:                    COMMON
Change controller:                 3GPP