Content-Type is an Internet standard for describing what bits mean. Example: image/jpeg
The first part is a small number of standard groups:
application, audio, image, message, model, multipart, text, video
Why don't we also have...
and maybe when there is more agreement on which parameters to use, number/wavefunction
I see it as a profound confusion in the world that we have no "number" Content Type but we have many far more advanced types like "model" which is normally for 3d shapes. Number should have preceded model. The world is profoundly backward in how people start with complexity and leave understanding what its made of for later, but when? When will number be seen as more important than complex structures made of many numbers? Content Type and Unicode are the closest thing we have to a global language, and we don't even have a word for number. Its no surprise complexity is running out of control and hardly anyone knows how things work anymore.
It will be http://sourceforge.net/projects/physicsmata
2.0 in a very basic form, and continuing to add plugins for more kinds of math and content...
I've finished the big parts of design and have moved on to coding what I hope to become an open standard for a shared Internet space which fits all possible shapes and patterns into networks of n-dimensional bell curves which are interchangible with hypercubes (using cached integral of bell curve) and interchangible with hyperspheres. A complex number is not a different kind of thing. Its a point in any 2 dimensions that the various objects choose to use that way. A bit is not a different kind of thing. Its what converges to bell curves when many are summed. You can push and pull numbers on parts of the bell curves, and every bell curve has a learn(emotionOrLearningRate) function.
Imagine an endless space of intelligent playdough we build tools and games and scientific frameworks in, and see how far we can take it to network minds together through the Internet.
Imagine a new kind of web browser that views every letter, every html page layout, every picture, every Content Type, as a bell curve of some number of dimensions (like fonts are 2d, and Google Sets would have maybe a billion dimensions, sparse data structures of course). When you type, letters and other symbols are pushed from the mouse pointer into the space. You can grab content from a few different websites and put it in a new bell curve, and for legal purposes we will call that a bookmark or multiple tabs in a web browser, each tab being a bell curve that sees that website or part of it. You're not a pirate for having 2 web browsers open at once, even though technically you have created a new content made of parts of both websites. Think of it as remote desktop between every piece of information in the system, pushing and pulling on eachother as you drag them around with the mouse or type new text into them. When you touch something on your screen, somebody on the other side of Earth would feel it in the vibration of their world, whatever parts are connected to that data on many paths. The Internet should be an endless space of thoughts, a shared dream we explore and create together, not a bunch of different websites with barbed wire fences and armed guards between them, not even letting Java applets communicate outside the server they came from, not letting any 2 computers send even 1 bit to eachother without going through a server which doesn't even have a word for number. Imagine the world is far simpler when you have words for its simple parts, words like number/bit, number/integer, number/real, number/complex, image/jpeg, vectorstream/mouse, vectorstream/nintendo-wii, vectorstream/brainchip, model/distanceconstraint... or lets keep it even simpler and not use different words for the constant form and streaming of them. Imagine that free speech doesn't have to use any words. Imagine an Internet made of thoughts flowing together in blobs of intelligent color. Imagine that our minds could merge with the Internet at a deep subconscious level without brain chips, just using the audio, visual, and game controller interfaces we already have, or did you think they don't read and write your brainwaves?
List of common media types
IANA manages the official registry of media types. Among others, it includes the following types:
For Multipurpose files:
application/atom+xml: Atom feeds
application/EDI-X12: EDI X12 data; Defined in RFC 1767
application/EDIFACT: EDI EDIFACT data; Defined in RFC 1767
application/octet-stream: Arbitrary binary data. Generally speaking this type identifies files that are not associated with a specific application. Contrary to past assumptions by software packages such as Apache this is not a type that should be applied to unknown files. In such a case, a server or application should not indicate a content type, as it may be incorrect, but rather, should omit the type in order to allow the recipient to guess the type.
application/ogg: Ogg, a multimedia bitstream container format; Defined in RFC 5334
application/pdf: Portable Document Format, PDF has been in use for document exchange on the Internet since 1993; Defined in RFC 3778
application/postscript: PostScript; Defined in RFC 2046
application/rdf+xml: Resource Description Framework; Defined by RFC 3870
application/rss+xml: RSS feeds
application/soap+xml: SOAP; Defined by RFC 3902
application/font-woff: Web Open Font Format; (candidate recommendation; use application/x-font-woff until standard is official)
application/xhtml+xml: XHTML; Defined by RFC 3236
application/xml: XML files; Defined by RFC 3023
application/xml-dtd: DTD files; Defined by RFC 3023
application/zip: ZIP archive files; Registered
application/gzip: Gzip, Defined in RFC 6713
audio/basic: ?-law audio at 8 kHz, 1 channel; Defined in RFC 2046
audio/L24: 24bit Linear PCM audio at 8–48 kHz, 1-N channels; Defined in RFC 3190
audio/mp4: MP4 audio
audio/mpeg: MP3 or other MPEG audio; Defined in RFC 3003
audio/ogg: Ogg Vorbis, Speex, Flac and other audio; Defined in RFC 5334
audio/vorbis: Vorbis encoded audio; Defined in RFC 5215
audio/vnd.rn-realaudio: RealAudio; Documented in RealPlayer Help
audio/vnd.wave: WAV audio; Defined in RFC 2361
audio/webm: WebM open media format
image/gif: GIF image; Defined in RFC 2045 and RFC 2046
image/jpeg: JPEG JFIF image; Defined in RFC 2045 and RFC 2046
image/pjpeg: JPEG JFIF image; Associated with Internet Explorer; Listed in ms775147(v=vs.85) - Progressive JPEG, initiated before global browser support for progressive JPEGs (Microsoft and Firefox).
image/png: Portable Network Graphics; Registered, Defined in RFC 2083
image/svg+xml: SVG vector image; Defined in SVG Tiny 1.2 Specification Appendix M
image/tiff: Tag Image File Format (only for Baseline TIFF); Defined in RFC 3302
message/http: Defined in RFC 2616
message/imdn+xml: IMDN Instant Message Disposition Notification; Defined in RFC 5438
message/partial: Email; Defined in RFC 2045 and RFC 2046
message/rfc822: Email; EML files, MIME files, MHT files, MHTML files; Defined in RFC 2045 and RFC 2046
For 3D models.
model/example: Defined in RFC 4735
model/iges: IGS files, IGES files; Defined in RFC 2077
model/mesh: MSH files, MESH files; Defined in RFC 2077, SILO files
model/vrml: WRL files, VRML files; Defined in RFC 2077
model/x3d+binary: X3D ISO standard for representing 3D computer graphics, X3DB binary files
model/x3d+vrml: X3D ISO standard for representing 3D computer graphics, X3DV VRML files
model/x3d+xml: X3D ISO standard for representing 3D computer graphics, X3D XML files
For archives and other objects made of more than one part.
multipart/mixed: MIME Email; Defined in RFC 2045 and RFC 2046
multipart/alternative: MIME Email; Defined in RFC 2045 and RFC 2046
multipart/related: MIME Email; Defined in RFC 2387 and used by MHTML (HTML mail)
multipart/form-data: MIME Webform; Defined in RFC 2388
multipart/signed: Defined in RFC 1847
multipart/encrypted: Defined in RFC 1847
For human-readable text and source code.
text/cmd: commands; subtype resident in Gecko browsers like Firefox 3.5
text/css: Cascading Style Sheets; Defined in RFC 2318
text/csv: Comma-separated values; Defined in RFC 4180
text/html: HTML; Defined in RFC 2854
text/plain: Textual data; Defined in RFC 2046 and RFC 3676
text/vcard: vCard (contact information); Defined in RFC 6350
text/xml: Extensible Markup Language; Defined in RFC 3023
video/mpeg: MPEG-1 video with multiplexed audio; Defined in RFC 2045 and RFC 2046
video/mp4: MP4 video; Defined in RFC 4337
video/ogg: Ogg Theora or other video (with audio); Defined in RFC 5334
video/quicktime: QuickTime video; Registered
video/webm: WebM Matroska-based open media format
video/x-matroska: Matroska open media format
video/x-ms-wmv: Windows Media Video; Documented in Microsoft KB 288102
video/x-flv: Flash video (FLV files)
List of common media subtype prefixes
For vendor-specific files.
application/vnd.oasis.opendocument.text: OpenDocument Text; Registered
application/vnd.oasis.opendocument.spreadsheet: OpenDocument Spreadsheet; Registered
application/vnd.oasis.opendocument.presentation: OpenDocument Presentation; Registered
application/vnd.oasis.opendocument.graphics: OpenDocument Graphics; Registered
application/vnd.ms-excel: Microsoft Excel files
application/vnd.openxmlformats-officedocument.spreadsheetml.sheet: Microsoft Excel 2007 files
application/vnd.ms-powerpoint: Microsoft Powerpoint files
application/vnd.openxmlformats-officedocument.presentationml.presentation: Microsoft Powerpoint 2007 files
application/vnd.openxmlformats-officedocument.wordprocessingml.document: Microsoft Word 2007 files
application/vnd.mozilla.xul+xml: Mozilla XUL files
application/vnd.google-earth.kml+xml: KML files (e.g. for Google Earth)
application/vnd.google-earth.kmz: KMZ files (e.g. for Google Earth)
application/vnd.dart: Dart files 
application/vnd.android.package-archive: For download apk files.