The Debian-Ports “unreleased” distribution is where porters can upload packages (sourcefully) with tweaks for specific architectures before the maintainer accepts them into unstable (though they’re based on the unstable version).
To cite Aurélien’s words:
Remember the rules: - You should upload a package to "unstable" only if it has been built without any changes to the sources or other hack. It should be uploaded without sources. - Other packages should be built for the "unreleased" suite, and should be uploaded with sources. Remember to also upload the .orig.tar.gz in that case.
Additionally, an upload to “unreleased” may not be arch:all only. It must include one arch-dependent package (e.g. arch:m68k) so dpo-minidak knows into which pool to put the package (this is a limitation of dpo-minidak, not a part of the rules). It must not target more than one architecture.
As for versioning (again, taking m68k as an example): If you add an upload of src:qt4-x11 which adds code, like, porting it to that architecture, without which it will never build or be useful, add “+m68k” or “+m68k.1” (later then “+m68k.2” etc.) to the version: qt4-x11_4.8.2+dfsg-3+m68k.2.dsc
If you merely patch the package to remove a build dependency or something like that, for bootstrapping or cycle breaking, it’s often better to add “~m68k.1” (later “~m68k.2”), so you can eventually upload the whole package. Example: libbluray_0.2.2-1~m68k.1.dsc – Example of how not to do it is avahi… sorry about that.
Reminder: Cross-built packages are normally never acceptable; packages built natively in an emulated or virtualised environment are subject to permit by the architecture porter team and normally not used.