KEYWORDS

The KEYWORDS variable as set in an ebuild informs the package manager for which architectures the ebuild is installable as well as if the ebuild is considered stable or still in testing phase.

An example KEYWORDS setting: KEYWORDS="alpha amd64 arm hppa ia64 m68k ~mips ppc ppc64 s390 sh sparc x86 ~sparc-fbsd ~x86-fbsd"

The prefix  is used to inform the package manager that the ebuild should be considered in "testing phase" and not ready for production usage just yet.