Arch-independent
A package is arch-independent if it doesn't need to be built on each architecture individually.
If possible a package should be marked as arch-intependent, to save the effort of building it on each architecture. Currently arch-independent packages are only built on the maintainers machine, and the packages they upload go straight in to the archive.
To mark a package as arch-independent the ?control file should contain
Architecture: all
Also see archdependent.