Registering experimental mime types

[Giovanni Campagna]

(warning: this is really long)

Studying Freedesktop's shared-mime-info, I noticed a lot of x- mime
types, which according to RFC4288 (Media Type Specifications and
Registration Procedures), section 3.4

"These types are unregistered, experimental, and for use only with the
active agreement of the parties exchanging them."

should not be used in a standard specification, as they cannot be
interoperable. In particular, it means that Web or Mail applications
cannot interoperate safely with the shared mime database, as HTTP and
MIME don't follow Freedesktop recommendations (but do follow IETF).

There are many of these, but some are more important, because they
represent types directly under Freedesktop responsibility and thus
should be formally registered with IANA. Also, I noted that for some
weird reasons, many types have a non experimental alias listed within
them. The database should be changed to expose the official media type,
instead of the x- type.

So, let's show the result of reading through the database. First of all,
the primary media types (before the slash, that is), which require an
RFC:

- x-content/*: as it is unlikely that IANA will allow registering
content/*, it may require renaming to unknown-content/*,
generic-content/*, or better to media-support/*, since that is what it
is used for currently
(as a side note: unix is a registered trademark)
- inode/*: this does not use x-, but it is not a registered media type,
according to http://www.iana.org/assignments/media-types/index.html -
registration is necessary, I think
- font/*: I'm not sure font faces can be stuffed inside application/*, a
new primary media type may be discussed

Secondly, I believe the following need full RFC standarization, as their
format is widely used and possibly already a recognized standard

- application/x-executable => application/executable
- application/x-core => application/core-file
- application/x-object => application/object-file
- application/x-sharedlib => application/shared-library
- application/x-bzip => application/bzip
- application/x-gzip => application/gzip
- application/x-lzma => application/lzma
- application/x-xz => application/xz
- application/x-tar => application/tar-archive
- application/x-bzip-compressed-tar => application/tar-archive+bzip
- application/x-compressed-tar => application/tar-archive+gzip
- application/x-lzma-compressed-tar => application/tar-archive+lzma
- application/x-xz => application/tar-archive+xz
- application/x-cd-image => application/iso-cd-image
- application/x-matroska => application/matroska
- video/x-matroska => video/matroska
- audio/x-matroska => audio/matroska
- audio/x-vorbis+ogg => audio/vorbis+ogg
- audio/x-flac+ogg => audio/flac+ogg
- audio/x-speex+ogg => audio/speex+ogg
- audio/x-speex => audio/speex
- video/x-theora+ogg => video/theora+ogg
- video/x-ogm+ogg => video/ogm+ogg
- application/x-pkcs7-certificates => application/pkcs7-certificates
- application/x-pkcs12 => application/pkcs12
- application/x-x509-ca-cert => application/x509-ca-cert
- text/x-adasrc => text/source-code-ada
- text/x-c++hdr => text/source-code-cpp-header (I think + is a reserved
char)
- text/x-c++src => text/source-code-cpp
- text/x-chdr => text/source-code-c-header
- text/x-csrc => text/source-code-c
- text/x-csharp => text/source-code-csharp
- text/x-fortran => text/source-code-fortran
- text/x-pascal => text/source-code-pascal
- text/x-sql => text/source-code-sql

Then, various freedesktop specific x- subtypes should go in the
freedesktop vendor subtree.
- application/x-xbel => application/vnd.freedesktop.xbel+xml
- application/x-desktop => application/vnd.freedesktop.desktop-entry
- application/x-theme => application/vnd.freedesktop.theme
- application/x-trash => application/vnd.freedesktop.backup-file
- application/x-zerosize => application/vnd.freedesktop.empty
- image/x-xcursor => image/vnd.freedesktop.cursor (or
image/vnd.xorg.cursor)
- image/x-xbitmap => image/vnd.xorg.bitmap
- image/x-xpixmap => image/vnd.xorg.pixmap


Other free software vendor specific media types (for vendors likely to
follow the xdg list)
- application/x-abiword => application/vnd.abiword.document
- application/x-dia-diagram => application/vnd.gnu.dia-diagram
- application/x-dia-shape => application/vnd.gnu.dia-shape
- application/x-deb => application/vnd.debian.package
- application/x-designer => application/vnd.nokia.qt-designer
- application/x-e-theme => application/vnd.enlightment.theme
- application/x-gettext-translation =>
application/vnd.gnu.gettext-machine-object
- application/x-glade => application/vnd.gnome.glade
- application/x-gnucash => application/vnd.gnu.cash
- application/x-gnumeric => application/vnd.gnu.spreadsheet
- application/x-gnuplot => application/vnd.gnu.plot
- application/x-karbon => application/vnd.kde.karbon
- application/x-kchart => application/vnd.kde.kchart
- application/x-kexi-connectiondata =>
application/vnd.kde.kexi-connectiondata
- application/x-kexiproject-shortcut =>
application/vnd.kde.kexi-shortcut
- application/x-kexiproject-sqlite? => application/vnd.kde.kexi-sqlite?
- application/x-kformula => application/vnd.kde.kformula
- application/x-killustrator => application/vnd.kde.killustrator
- application/x-kivio => application/vnd.kde.kivio
- application/x-kontour => application/vnd.kde.kontour
- application/x-kpovmodeler => application/vnd.kde.kpovmodeler
- application/x-kpresenter => application/vnd.kde.kpresenter
- application/x-krita => application/vnd.kde.krita
- application/x-kspread => application/vnd.kde.kspread
- application/x-kspread-crypt => application/vnd.kde.kspread-crypt
- application/x-ksysv-package => application/vnd.kde.ksysv-package
- application/x-kugar => application/vnd.kde.kugar
- application/x-kword => application/vnd.kde.kword
- application/x-kword-crypt => application/vnd.kde.kword-crypt
- application/x-mozilla-bookmarks => application/vnd.mozilla.bookmarks
- application/x-nautilus-link => application/vnd.gnome.nautilus-link
- application/x-oleo => application/vnd.gnu.oleo
- application/x-profile => application/vnd.gnu.profile
- application/x-rpm => application/vnd.redhat.package
- application/x-shared-library-la => application/vnd.gnu.libtool-archive
- image/x-compressed-xcf => image/vnd.gnu.compressed-xcf
- image/x-xcf => image/vnd.gnu.xcf
- message/x-gnu-rmail => message/vnd.gnu.rmail
- text/x-vala => text/vnd.gnome.source-code-vala
- text/x-emacs-lisp => text/vnd.gnu.emacs-lisp
- text/x-gettext-translation => text/vnd.gnu.gettext
- text/x-gettext-translation-template => text/vnd.gnu.gettext-template
- text/x-moc => text/vnd.nokia.qt-moc
- text/x-rpm-spec => text/vnd.redhat.package-spec
- application/x-xpinstall => application/vnd.mozilla.xpinstall

(I marked every application/x-k* as part of the KDE project, some may
actually be independent apps for the KDE platform. Nevertheless, there
are a lot of k* mime types, it would be good for those apps to go for
standard defined formats)

Then the standard Unix file types (beyond those covered by inode/*).
In this case, and if this proposal is approved, the Open Group should be
asked for a formal registration.
- application/x-archive => application/vnd.unix.ar
- application/x-awk => application/vnd.unix.awk
- application/x-bcpio => application/vnd.unix.binary-cpio
- application/x-compress => application/vnd.unix.compress
- application/x-cpio => application/vnd.unix.cpio
- application/x-m4 => application/vnd.unix.m4
- application/x-reject => application/vnd.unix.patch-reject
- application/x-shar => application/vnd.unix.shell-archive
- application/x-shellscript => application/vnd.unix.shell-script
- application/x-tarz => application/tar-archive+vnd.unix.compress (is
this legal?)
- application/x-troff-man => application/vnd.unix.manual-page
- application/x-troff-man-compressed =>
application/vnd.unix.manual-page-compressed
- text/x-makefile => text/vnd.unix.makefile
- text/x-patch => text/vnd.unix.patch

I'm not sure about the following
- text/x-authors
- text/x-changelog (=> text/vnd.gnu.changelog ?)
- text/x-copying (=> text/vnd.gnu.license ?)
- text/x-credits
- text/x-install
- text/x-log
- text/x-readme
- text/x-uri (=> text/vnd.freedesktop.uri ?)

A lot more experimental media types exist, but cannot be changed without
cooperation with the responsible organization, which should be
contacted. I have a full list if someone wants it.

I believe this change will help the shared-mime-info becoming the
de-facto standard for converting from a file (with a name and some data)
to a full media type, helping the adoption of Freedesktop and Internet
standards.

I know it will require a lot of work, not only changing the database and
sending mails to IANA, but also updating the applications accordingly,
but I think it is worth it.

Any comments appreciated

Giovanni