Internet media type

An Internet media type,^[1] originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value is such a type, is a two-part identifier for file formats on the Internet. The identifiers were originally defined in RFC 2046 for use in e-mail sent through SMTP, but their use has expanded to other protocols such as HTTP and SIP.

A media type is composed of at least two parts: a type, a subtype, and one or more optional parameters. For example, subtypes of text type have an optional charset parameter that can be included to indicate the character encoding, and subtypes of multipart type often define a boundary between parts.

Types or subtypes that begin with "x-" are nonstandard -- they cannot be registered with IANA.^[2] Subtypes that begin with vnd. are vendor-specific; subtypes in the personal or vanity tree begin with prs..^[3]

List of common media types

IANA manages a registry of media types and character encodings. The organization makes a list available to the public through the Web. Some of the more notable media types used on the Web are listed below:

• Type application: Multipurpose files
  • application/EDI-X12: EDI X12 data; Defined in RFC 1767
  • application/EDIFACT: EDI EDIFACT data; Defined in RFC 1767
  • application/javascript: JavaScript; Defined in RFC 4329
  • application/octet-stream: Arbitrary byte stream. This is thought of as the "default" media type used by several operating systems, often used to identify executable files, files of unknown type, or files that should be downloaded in protocols that do not provide a separate "content disposition" header. RFC 2046 specifies this as the fallback for unrecognized subtypes of other types.
  • application/ogg: Ogg, a multimedia bitstream container format; Defined in RFC 3534
  • application/xhtml+xml: XHTML; Defined by RFC 3236
  • application/xml-dtd: DTD files; Defined by RFC 3023
  • application/json: JavaScript Object Notation JSON; Defined in RFC 4627
  • application/zip: ZIP archive files; Registered^[4]
• Type audio: Audio
  • audio/mpeg: MP3 or other MPEG audio; Defined in RFC 3003
  • audio/x-ms-wma: Windows Media Audio; Documented in Microsoft KB 288102
  • audio/vnd.rn-realaudio: RealAudio; Documented in RealPlayer Customer Support Answer 2559
  • audio/x-wav: WAV audio
• Type example
• Type image
  • image/gif: GIF image; Defined in RFC 2045 and RFC 2046
  • image/jpeg: JPEG JFIF image; Defined in RFC 2045 and RFC 2046
  • image/png: Portable Network Graphics; Registered^[5]
  • image/tiff: Tag Image File Format; Defined in RFC 3302
  • image/vnd.microsoft.icon: ICO image; Registered^[6]
• Type message
• Type model: 3D models
• Type multipart: Archives and other objects made of more than one part
  • multipart/mixed: MIME E-mail; Defined in RFC 2045 and RFC 2046
  • multipart/alternative: MIME E-mail; Defined in RFC 2045 and RFC 2046
  • multipart/related: MIME E-mail; Defined in RFC 2387 and used by MHTML (HTML mail)
  • multipart/form-data: MIME Webform; Defined in RFC 2388
• Type text: Human-readable text and source code
  • text/css: Cascading Style Sheets; Defined in RFC 2318
  • text/html: HTML; Defined in RFC 2854
  • text/javascript (Obsolete): JavaScript; Defined in and obsoleted by RFC 4329 in order to discourage its usage in favor of application/javascript
  • text/plain: Textual data; Defined in RFC 2046 and RFC 3676
  • text/xml: Extensible Markup Language; Defined in RFC 3023
• Type video: Video
  • video/mpeg: MPEG-1 video with multiplexed audio; Defined in RFC 2045 and RFC 2046
  • video/mp4: MP4 video; Defined in RFC 4337
  • video/quicktime: QuickTime video; Registered^[7]
  • video/x-ms-wmv: Windows Media Video; Documented in Microsoft KB 288102

• Type vnd: Vendor Specific Files ^[8]
  • application/vnd.ms-excel: Microsoft Excel files
  • application/vnd.ms-powerpoint: Microsoft Powerpoint files
  • application/msword: Microsoft Word files
  • application/vnd.mozilla.xul+xml: Mozilla XUL files

• Type x: Non-standard files^[8]
  • application/x-dvi: Digital Video files in DVI format
  • application/x-httpd-php: PHP files
  • application/x-httpd-php-source: PHP source files
  • application/x-latex: LATEX files
  • application/x-shockwave-flash: Adobe Flash files; Documented in Adobe TechNote tn_4151 and Adobe TechNote tn_16509
  • application/x-stuffit: StuffIt archive files
  • application/x-rar-compressed: RAR archive files
  • application/x-tar: Tarball files

References

1. ^ "Internet Media Type registration, consistency of use". W3C (2002-06-03). Retrieved on 2006-11-29.
2. ^ Freed, N. (November 1996). "RFC 2045 - Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies". IETF. Retrieved on 2006-11-29.
3. ^ Freed, N.; Klensin, J. (December 2005). "RFC 4288 - Media Type Specifications and Registration Procedures". IETF. Retrieved on 2008-06-14.
4. ^ http://www.iana.org/assignments/media-types/application/zip
5. ^ http://www.iana.org/assignments/media-types/image/png
6. ^ http://www.iana.org/assignments/media-types/image/vnd.microsoft.icon
7. ^ http://www.iana.org/assignments/media-types/video/quicktime
8. ^ ^{a b} "ContentType". Retrieved on 2008-04-24.

See also

• XML and MIME

External links

• IANA MIME media types list
• RFC 2045, RFC 2046 - Multipurpose Internet Mail Extensions (MIME), parts 1 and 2